HDAC8 inhibitors for treating cancer

ABSTRACT

Provided herein, inter alia, are compound and methods of treating cancer by inhibiting HDAC8.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US2014/051876, filed Aug. 20, 2014, which claims the benefit of U.S.Provisional Application No. 61/868,073, filed Aug. 20, 2013. Thedisclosure of each of the prior applications is considered part of andis incorporated by reference in the disclosure of this application

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH AND DEVELOPMENT

This invention was made with Government support under grant number P30CA033572 awarded by the National Cancer Institute. The Government hascertain rights in the invention.

REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAMLISTING APPENDIX SUBMITTED AS AN ASCII FILE

The Sequence Listing written in file 48440_535N01US_ST25.TXT, createdApr. 28, 2016, 5.160 bytes, machine format IBM-PC, MS-Windows operatingsystem, is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Histone deacetylases (HDACs) play a role in the reversible acetylationof histones, transcription factors, and other proteins, which areassociated with chromatin remodeling and regulation of gene expression.Acute myeloid leukemia (AML) arises, in part, from disorderedhematopoiesis as a consequence of multiple cooperative mutations oralternations disrupting differentiation, proliferation and survivalprograms in hematopoietic progenitors. Recurrent chromosomalabnormalities in AML frequently involve transcription factor fusionproteins that contribute to unique etiology and prognosis (1).Chromosomal 16 inversion, inv(16)(p13.1q22) or t(16;16)(p13.1;q22) isfound in approximately 5-12% of AML patients and is associated withdismal prognosis. Accordingly, new treatments for AML patients arenecessary. Provided herein are solutions to these and other problems inthe art.

BRIEF SUMMARY OF THE INVENTION

It has been discovered herein, inter alia, that HDAC8 activity is linkedto cancer. Thus, provided herein are compounds and methods for treatingcancer with HDAC8 inhibitors. In a first aspect is a compound having theformula:

A is cycloalkyl, heterocycloalkyl, aryl, or heteroaryl. X is —C(R⁴)═ or—N═. Y is a bond, —N(R⁵)—, —O—, or —S—. L¹ is a bond, —C(O)—, —C(O)O—,—O—, —S—, —N(R⁶)—, —C(O)N(R⁶)—, —S(O)_(n6)—, —S(O)N(R⁶)—, substituted orunsubstituted alkylene, substituted or unsubstituted heteroalkylene,substituted or unsubstituted cycloalkylene, substituted or unsubstitutedheterocycloalkylene, substituted or unsubstituted arylene, orsubstituted or unsubstituted heteroarylene. R¹ is halogen, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —OR^(1A), —C(O)R^(1A), —NR^(1A)R^(1B),—C(O)OR^(1A), —C(O)NR^(1A)R^(1B), —NO₂, —SR^(1A), —S(O)_(n1)R^(1A),—S(O)_(n1)OR^(1A), —S(O)_(n1)NR^(1A)R^(1B), —NHNR^(1A)R^(1B),—ONR^(1A)R^(1B), —NHC(O)NHNR^(1A)R^(1B), substituted or unsubstitutedalkyl, substituted or unsubstituted heteroalkyl, substituted orunsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl,substituted or unsubstituted aryl, or substituted or unsubstitutedheteroaryl. R² is halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(2A),—C(O)R^(2A), —NR^(2A)R^(2B), —C(O)OR^(2A), —C(O)NR^(2A)R^(2B), —NO₂,—SR^(2A), —S(O)_(n2)R^(2A), —S(O)_(n2)OR^(2A), —S(O)_(n2)NR^(2A)R^(2B),—NHNR^(2A)R^(2B), —ONR^(2A)R^(2B), —NHC(O)NHNR^(2A)R^(2B), substitutedor unsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R³ is independently halogen, —N₃, —CF₃, —CCl₃,—CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂,—S, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, substituted or unsubstitutedC₁-C₅ alkyl, or substituted or unsubstituted 2 to 5 memberedheteroalkyl. R⁴ is hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃,—CN, —OR^(4A), —C(O)R^(4A), —NR^(4A)R^(4B), —C(O)OR^(4A),—C(O)NR^(4A)R^(4B), —NO₂, —SR^(4A), —S(O)_(n4)R^(4A), —S(O)_(n4)OR^(4A),—S(O)_(n4)NR^(4A)R^(4B), —NHNR^(4A)R^(4B), —ONR^(4A)R^(4B),—NHC(O)NHNR^(4A)R^(4B), substituted or unsubstituted C₁-C₅ alkyl, orsubstituted or unsubstituted 2 to 5 membered heteroalkyl. R⁵ ishydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(5A),—C(O)R^(5A), —NR^(5A)R^(5B), —C(O)OR^(5A), —C(O)NR^(5A)R^(5B), —NO₂,—SR^(5A), —S(O)_(n5)R^(5A), —S(O)_(n5)OR^(5A), —S(O)_(n5)NR^(5A)R^(5B),—NHNR^(5A)R^(5B), —ONR^(5A)R^(5B), —NHC(O)NHNR^(5A)R^(5B), substitutedor unsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R⁶ is hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(6A), —C(O)R^(6A), —NR^(6A)R^(6B), —C(O)OR^(6A),—C(O)NR^(6A)R^(6B), —NO₂, —SR^(6A), —S(O)_(n6)R^(6A), —S(O)_(n6)OR^(6A),—S(O)_(n6)NR^(6A)R^(6B), —NHNR^(6A)R^(6B), —ONR^(6A)R^(6B),—NHC(O)NHNR^(6A)R^(6B), substituted or unsubstituted alkyl, substitutedor unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl. R^(1A),R^(1B), R^(2A), R^(2B), R^(4A), R^(4B), R^(5A), R^(5B), R^(6A), andR^(6B) are independently hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂,—COOH, —CONH₂, —NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂,—ONH₂, —NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH,—OCF₃, —OCHF₂, substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl. Thesymbols n1, n2, n4, n5, and n6 are independently 1, 2, or 3. The symbolm1 is 0, 1, 2, 3, or 4. The symbol m2 is 0, 1, 2, 3, 4, 5, or 6. Thesymbol m3 is 0, 1, or 2.

Also provided herein are methods of treating cancer. In one aspect is amethod of treating cancer in a subject in need thereof by administeringan effective amount of an HDAC8 inhibitor to said subject.

Further provided herein are methods of inhibiting HDAC8 mediateddeacetylation of p53. In one aspect is a method of inhibiting HDAC8mediated deacetylation of p53 by contacting HDAC8 with a HDAC8 inhibitorin the presence of p53, thereby inhibiting HDAC8 deacetylation of p53.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1G. CBFβ-SMMHC expression impaired p53 target gene inductionand reduced acetylation of p53. FIG. 1A: Relative expression of p53target genes including (in order left to right, top to bottom) p21,Mdm2, Bax, Bid, Puma, Gadd45b, LincRNA-p21 and Stag1 in 32D-CM or32D-CBFβ cells, determined by qRT-PCR. Shown are fold induction 24 hafter 3 Gy IR relative to non-IR (mean+/−SD) performed in replicate andthree independent experiments. FIG. 1B: Western blot analysis of Ac-p53,p53, CM, CBFβ and HDAC8 at indicated time points (2, 4, 6 and 12 h)after IR in 32D-CM or 32D-CBFβ cells. β-actin served as loading control.FIG. 1C: Western blot time course analysis (2, 4, 6 and 12 h) of Ac-p53,p53, CM, CBFβ after IR in BM progenitor cells isolated fromCM-expressing pre-leukemic or control mice. β-actin served as loadingcontrol. FIG. 1D: Western blot of Ac-p53, p53, CM, CBFβ in Cbfb^(56M/+)BM progenitor cells transduced with MIG-Cre and IR (3 Gy, 6 h). β-actinserved as loading control. FIG. 1E: Western blot of Ac-p53, p53, CM,CBFβ in 32D-CM cells expressing control (Ctrl)-shRNA or CM shRNA (A3,D4) 6 h after 3 Gy IR. β-actin served as loading control. FIG. 1F:Western blot of CM and β-actin in sorted leukemic BM cells transducedwith non-silencing ctrl-shRNA or CM shRNA (A3, D4). FIG. 1G: Histogramdepicting relative expression of p53 target genes including (in orderleft to right) p21, Gadd45b, LincRNA-p21 Bax, Puma, and Bid in sortedleukemic BM cells transduced with non-silencing ctrl-shRNA or CM shRNA(A3, D4). Shown are fold change (mean+/−SD) relative to ctrl-shRNAexpressing cells, performed in triplicate. Ordering (left to right forp53 target): ctrl, A3, A4.

FIGS. 2A-2F. CBFβ-SMMHC fusion protein aberrantly interacts with p53.FIG. 2A: Co-IP and immunoblot (IB) analysis in 32D-CM (top) or 32D-CBFβ(bottom) cells using anti-p53 or anti-mouse IgG for IP, and anti-p53(left) or anti-CBFβ (right) for IB. Shown are representative of morethan three independent experiments. FIG. 2B: Co-IP (anti-FLAG) and IB(anti-p53) analysis in 32D-Flag, 32D-CBFβ or 32D-CM cells. Input of CBFβor CM are shown using anti-FLAG (IP, IB). FIG. 2C: Co-IP and IB analysisin control BM progenitor cells (lane 1 from left), CM-expressingpre-leukemic or leukemic BM cells without IR (left) or pre-leukemic BMcells after IR (right). IP was performed with anti-CBFβ and IB wasperformed with anti-p53 (top) or anti-CBFβ (middle). Bottom panel showswestern blot using anti-p53. FIG. 2D: Co-IP (anti-FLAG) and IB(anti-p53) analysis in nuclear and cytoplasmic fractions prepared fromthe indicated cell lines. Western blot analyses for CM, p53, and HistoneH3 for each fraction are shown. FIG. 2E: DUOLINK® in situ proximityligation assay (PLA) using mouse anti-CBFβ antibody plus rabbit anti-p53antibody and PLA probes. Punctuate red fluorescent spots indicateintermolecular protein interactions (left). DAPI-stained nuclei areshown in blue (center) and GFP reporter indicates transduced cells(right). Shown are representative images. FIG. 2F. Co-IP and IB ininv(16)⁺ AML (163, 987) or non-inv(16) AML (467, 865) CD34⁺ cells 3 hafter IR. Co-IP was performed using anti-p53 (DO-1) or anti-mouse IgG,and IB was performed with anti-CBF β (top) or anti-p53 antibodies(bottom).

FIGS. 3A-3F. CBFβ-SMMHC recruits p53 and HDAC8 in a protein complexthrough distinct protein regions. FIG. 3A: Sequential co-IP and IBanalysis in 32D-CBFβ or 32D-CM cells using anti-HDAC8 for the primaryIP, followed by IP using anti-CBFβ, and IB with anti-p53. Cells wereeither not IR (left panel) or received 3 Gy IR (right panel). FIG. 3B:Sequential co-IP and IB analysis in 32D-CBFβ or 32D-CM cells usinganti-p53 for the primary IP, followed by IP using anti-CBFβ, and IB withanti-HDAC8. FIG. 3C: Illustration of CM deletion variants (left) used inCo-IP (anti-p53) and IB (anti-CBFβ or anti-p53) analysis (right). Arrowscorrespond to the expected size of CM variants. FIG. 3D: DUOLINK® insitu PLA in 32D cells expressing FL-CM or deletion mutants d134, d179 orDC95 using mouse anti-CBFβ plus rabbit anti-p53 and PLA probes. Redfluorescent spots indicate CM-p53 protein interactions (top), DAPIstaining is in blue (center) and GFP reporter indicates transduced cells(bottom). Shown are representative images. FIG. 3E: Western blotting ofHdac8 in 32D-CM cells expressing non-silencing control shRNA orHdac8-shRNA (sh1 or sh2) (left). Co-IP (IgG or anti-p53) and IB(anti-CBFβ or anti-p53) analysis in shRNA (control, sh1 or sh2)expressing cells (right). FIG. 3F: In situ PLA in 32D-CM cellsexpressing control shRNA or Hdac8-shRNA (sh1 or sh2) using mouseanti-CBFβ plus rabbit anti-p53 and PLA probes. Spots indicate CM-p53protein interactions (left), DAPI staining (center) and GFP reporterindicates transduced cells (right). Representative images are shown.

FIGS. 4A-4E. HDAC8 mediates the deacetylation of p53 inCBFβ-SMMHC-expressing cells. FIG. 4A: Western blotting of Hdac8, Ac-p53(K379), and total p53 levels after shRNA-mediated knock-down in 32D-CMcells in response to IR (3 Gy). Levels of β-actin were detected asloading control. FIG. 4B: Western blotting of Ac-p53 (K379), p53 andHdac8 in 32D-CM cells treated with HDAC8 inhibitor PCI-34051, 22d orNutlin-3 at doses indicated for 6 h. FIG. 4C: Western blotting of Ac-p53(K379), p53 in CM, ΔC95 compared to CBFβ or FLAG expressing 32D cells at2 h or 4 h after IR (3 Gy). FIG. 4D: Fold induction of p53 target genesincluding p21, Mdm2, Bax, Bid, Puma, Gadd45b, LincRNA-p21 and Stag1 in32D-CBFβ, CM or CM-ΔC95 expressing cells, determined by qRT-PCR. Shownare fold induction 24 h after 3 Gy IR relative to non-IR (mean+/−SD)performed in triplicate and two independent experiments. FIG. 4E: Foldactivation of p53 target genes, Bax, Puma, p21, Gadd45b and LincRNA-p21in 32D-CM cells treated with HDAC8i PCI-34051 (10 μM) or 22d (10 μM) for16 h, determined by qRT-PCR. Relative expression of each target gene wasnormalized to levels of Hprt. Shown are fold activation compared tolevels in vehicle treated cells (dashed line). Results represent themean±SD of triplicated assays.

FIGS. 5A-5G. Pharmacological inhibition of HDAC8 selectively activatesp53, reduces proliferation and induces p53-dependent apoptosis ininv(16)⁺ AML CD34⁺ cells. FIG. 5A: Relative expression level of HDAC8 innormal (NL) PBSC (n=7) or inv(16)⁺ AML (n=7) CD34⁺ cells determined byqRT-PCR. Levels of HDAC8 expression were normalized to levels of ACTB ineach sample. Dashed line indicates the average of all NL PBSC samples(set to an arbitrary value of 1). Each dot represents average oftriplicated result from an individual patient and line indicatesmean±SEM (standard error the mean) of each all samples (p=0.0003). FIG.5B: Relative proliferation of inv(16)⁺ AML CD34⁺ (n=7) or normal CD34⁺(n=7) cells treated with indicated dose of 22d HDAC8i for 48 h, asdetermined by Cell Titer-Glo Luminescent Cell Viability Assay andnormalized to vehicle treated controls. Each dot represents anindividual subject and lines indicate mean±SEM. * P<0.05; ** P<0.01; ***P<0.001. FIG. 5C: Percent apoptosis determined by Annexin V labeling ofinv(16)⁺ AML CD34⁺ (n=6) or normal CD34⁺ (n=5) cells treated withindicated doses of 22d for 48 h, and normalized to vehicle treatedcontrols. Each dot represents an individual patient and lines indicatemean±SEM. * P<0.05; ** P<0.01; *** P<0.001. FIG. 5D: Western blotting ofAc-p53 (K382), and p53 levels in inv(16)⁺ AML CD34⁺ cells treated with22d (10 μM) or Nutlin-3 (2.5 μM) for 6 h. Levels of β-actin weredetected as loading control. Shown are representative results from fourpatients. FIG. 5E: Fold induction of p53 target genes in inv(16)⁺ AMLCD34⁺ (n=9) or normal CD34⁺ (n=7) cells treated with 22d (10 μM) for 16h, determined by qRT-PCR. Relative expression of each target gene wasnormalized to levels of ACTB. Each dot represents an individual subjectand lines indicate mean±SEM. Dash line indicates levels in vehicletreated cells. * P<0.05; ** P<0.01; *** P<0.001. FIG. 5F: RepresentativeFACS plot of Annexin V/DAPI labeling in inv(16)⁺ AML CD34⁺ cellstransduced with a pLKO-GFP vector expressing p53 shRNA (GFP⁺) andtreated with 22d for 48 h. FIG. 5G: Relative survival of sorted GFP+inv(16)⁺ AML CD34⁺ cells expressing p53 shRNA (open diamond) ornon-silencing control (solid dot) and treated with indicated doses of22d for 48 h. Each dot represents an individual patient and linesindicate mean±SEM.

FIGS. 6A-6G. Inhibiting HDAC8 by pharmacological inhibitor 22deliminates LSC engraftment and AML propagation. FIG. 6A: Schematicillustration of experimental design. Cbfb^(+/56M)Mx1Cre orCbfb^(+/56M)Mx1Cre/tdTomato⁺ mice were induced with pIpC and AML cellswere isolated from bone marrow of moribund mice, treated with 22d orvehicle for 48 or 72 h and transplanted into sub-lethally irradiated(6.5 Gy) C57Bl/6 congenic mice. Progression of AML was monitored byengraftment of AML cells in peripheral blood (PB) over time (4, 8 weeks)and engraftment in bone marrow and spleen was analyzed 8 weeks aftertransplantation. A cohort of mice was monitored for AML development anddisease-free survival. FIG. 6B: Engraftment of dTomato⁺ AML cells in thePB 4 weeks (n=7; p=0.0006) or 8 weeks (vehicle, n=5; 22d, n=7; p=0.0025)after transplantation. Results represent mean±SD. FIG. 6C:Representative images of spleens from mice transplanted with vehicletreated cells (top) or 22d treated cells (bottom) 8 weeks aftertransplantation. FIG. 6D: Representative FACS plots of engrafteddTomato⁺/cKit⁺ AML cells in the bone marrow or spleen 8 weeks aftertransplantation. Shown are representative frequencies of dTomato⁺/cKit⁺cells in individual transplanted mice. FIG. 6E: Frequency of AML cells(dTomato⁺/cKit⁺) in the bone marrow of mice transplanted with vehicletreated (n=5) or 22d treated cells (n=7). Each dot represent resultsfrom individual mouse and line indicate median. **p=0.0025. FIG. 6F:Frequency of AML cells (dTomato⁺/cKit⁺) in the spleen of micetransplanted with vehicle treated (n=5) or 22d treated cells (n=7). Eachdot represent results from an individual mouse and lines indicatemedian. **p=0.0025. FIG. 6G: Survival curve of mice transplanted withAML cells treated with 22d (n=10) or vehicle (n=1). **p=0.0025

FIG. 7A-7I. In vivo administration of 22d significantly reduce AMLburden and abrogate LSC activity. FIG. 7A: Schematic illustration ofexperimental design. Cbfb^(+/56M)Mx1Cre/tdTomato⁺ mice were induced withpIpC and AML cells were isolated from bone marrow of moribund mice andtransplanted into sub-lethally irradiated (6.5 Gy) C57Bl/6 congenicmice. After 5-6 weeks, mice were randomized into two groups, one groupwas treated with vehicle and the other treated with 22d byintraperitoneal injection (50 mg/kg/dose) twice a day for 2 weeks. AMLengraftment was analyzed at the end of the treatment period, andtransplanted into 2^(nd) recipients. Recipients were analyzed forengraftment at 8 weeks or monitored for leukemia onset and survival.FIG. 7B: Representative FACS plots of engrafted dTomato+/cKit+ AML cellsin the bone marrow after the 2-week treatment with vehicle (top) or 22d(bottom). FIG. 7C: Frequency of AML cells (dTomato⁺/cKit⁺) in the bonemarrow of mice treated with vehicle (n=13) or 22d (n=13) for 2 weeks.Each dot represent results from an individual mouse and lines indicatemedian±SEM. **p=0.0097. FIG. 7D: Total number of AML cells(dTomato⁺/cKit⁺) in the bone marrow of mice treated with vehicle (n=13)or 22d (n=13) for 2 weeks. Each dot represent results from an individualmouse and lines indicate median±SEM. *p=0.01. FIG. 7E: RepresentativeFACS plots of dTomato⁺/cKit⁺ AML cells in the bone marrow of 2^(nd)transplant recipients whom received BM from vehicle treated (top) or 22dtreated (bottom) mice. Mice were analyzed 8 weeks after transplantation.FIG. 7F: Frequency of AML cells in the bone marrow of 2^(nd) transplantrecipients received BM from vehicle treated (n=5) or 22d treated (n=4)mice. ***p<0.0001. FIG. 7G. Total number of AML cells in the bone marrowof 2^(nd) transplant recipients received BM from vehicle treated (n=5)or 22d treated (n=4) mice. ***p=0.0006. FIG. 7H: Spleen weight of 2^(nd)transplant recipient who received BM from vehicle treated (n=5) or 22dtreated (n=4) mice, 8 weeks after transplantation. *p=0.0159. FIG. 7I:Survival curve of 2^(nd) transplant recipients of vehicle treated (n=5)or 22d treated (n=4) BM.

FIG. 8. Cartoon depicting proposed model illustrating HDAC8-mediated p53inactivation contributes to CBFβ-SMMHC-associated AML LSC maintenance.The leukemogenic fusion protein CBFβ-SMMHC recruits p53 and HDAC8 intoan aberrant protein complex, thereby inhibiting the tumor suppressor p53activity is through aberrant deacetylation by HDAC8. Inhibiting HDAC8deacetylase activity by HDAC8 selective pharmacological inhibitor leadsto reactivation of p53 in AML LSCs. This novel p53-inactivatingmechanism highlights a promising approach to restore p53 activity, andenhance targeting of AML LSCs.

FIG. 9. CM interacts with mostly deacetylated p53 proteins. DUOLINK® insitu PLA in 32D-CM cells using mouse anti-CBFβ, rabbit anti-p53 orAc-p53 (K379) and PLA probes. Red fluorescent spots indicate CM-p53 orCM-Ac-p53 protein interactions (top), DAPI-stained nucleus is in blue(center) and GFP reporter indicates transduced cells (bottom).

FIG. 10. HDAC8 interacts with CM C-terminal region. DUOLINK® in situ PLAin 32D cells expressing FL-CM, deletion mutant ΔC95 using mouseanti-CBFβ, xrabbit anti-HDAC8 and PLA probes. Fluorescent spots indicateCM-HDAC8 protein interactions (top), DAPI-stained nucleus is in center,and GFP reporter indicates transduced cells (bottom).

FIG. 11. Acetylation of p53 is not affected in CM deletion mutantsunable to interact with p53 or HDAC8. Western blot analysis of Ac-p53(K379), total p53 levels in 32D cells expressing CBFβ, CM, CM-d134,CM-d179 or CM-ΔC95 deletions. Cell lysate were isolated before, 2 h or 4h after IR (3 Gy). Levels of β-actin were detected as loading control.

FIGS. 12A-12B. HDAC8i induces activation of p53 targets in progenitorcells expressing endogenous levels of CM. Fold activation of p53 targetgenes in pre-leukemic (FIG. 12A, n=4) or leukemic (FIG. 12B, n=4)progenitor cells expressing CM, treated with HDAC8i 22d (10 μM) for 16h, determined by qRT-PCR. Relative expression of each target gene wasnormalized to levels of Hprt. Shown are fold activation compared tolevels in vehicle treated cells (dashed line). Results represent themean±SD.

FIGS. 13A-13B. HDAC8i treatment selectively induce of apoptosis and p53acetylation in inv(16)⁺ AML CD34⁺ cells. FIG. 12A: Percent survivaldetermined by Annexin V labeling of inv(16)⁺ AML CD34⁺ (n=6),non-inv(16) AML (n=4) or normal CD34⁺ (n=5) cells treated with indicateddoses of 22d for 48 h, and normalized to vehicle treated controls. Shownare mean±SEM. * P<0.05; ** P<0.01; *** P<0.001. FIG. 12B: Westernblotting of Ac-p53 (K382), and p53 levels in non-inv(16) AML CD34⁺ cellstreated with 22d (10 mM) for 6 h. Levels of β-actin were detected asloading control.

FIG. 14A-14B. Confirmation of p53 knock-down by lentivirus expressingshRNA. FIG. 14A: Change in p53 expression level in GFP sorted MV4-11cells transduced with pLKO.1-GFP lentivirus expressing sh-p53 ornon-silencing control (sh-ctrl) normalized to levels of b-actin. Shownare mean±SEM. FIG. 14B: Western blot analysis of p53 in GFP sortedMV4-11 cells transduced with pLKO.1-GFP lentivirus expressing sh-p53 orsh-ctrl. Levels of b-actin serve as loading control.

FIGS. 15A-15F. HDAC8i 22d treatment significantly reduces engraftmentand progression of AML. FIG. 15A. Weight of spleens isolated micetransplanted with vehicle treated (n=5) or 22d treated cells (n=7). Eachdot represent results from individual mice and line indicate median.p=0.0025. FIG. 15B. Total number of AML cells (dTomato⁺/cKit⁺) in thebone marrow (2 femurs and 2 tibia) of mice transplanted with vehicletreated (n=5) or 22d treated cells (n=7). Each dot represent resultsfrom individual mice and line indicate median. p=0.0025. FIG. 15C. Totalnumber of AML cells (dTomato⁺/cKit⁺) in the spleen of mice transplantedwith vehicle treated (n=5) or 22d treated cells (n=7). Each dotrepresent results from individual mice and line indicate median.p=0.0025. FIG. 15D. The frequency of dTomato+ cells in the PB 8 weeksafter transplantation of 2×10⁶ AML cells treated with 22d or vehicle exvivo for 48 h (n=4). Each dot represent results from individual mice andline indicate mean±SEM. p=0.0357. FIG. 15E. The frequency ofdTomato+/ckit+ cells in the BM 28 weeks after transplantation of 2×10⁶cells treated with 22d (n=4) or vehicle (n=2; 2 had succumbed to AML) exvivo for 48 h (n=4). Each dot represent results from individual mice andline indicate mean±SEM. FIG. 15F. Survival curve of mice transplantedwith 2×10⁶ AML cells treated with 22d or vehicle (n=4).

FIGS. 16A-16B. CBFb-SMMHC does not affect p53 mRNA expression. FIG. 16A:Relative expression of p53 mRNA in 32D-Cbfb or 32D-CM cells asdetermined by qRT-PCR. Shown are mean±SD. FIG. 16B: Relative expressionof p53 mRNA in pre-leukemic progenitor subsets sorted from inducedCbfb^(+/56M)Mx1Cre, analyzed by qRT-PCR. Phenotypic progenitor subsetsare defined as myeloid progenitors (MPs) (Lin⁻/ckit⁺/Sca1⁻), commonmyeloid progenitors (CMPs) (Lin⁻/ckit⁺/Sca1⁻/CD34⁺/FcgR^(lo)),granulocyte-macrophage progenitors (GMPs)(Lin⁻/ckit⁺/Sca1⁻/CD34⁺/FcgR^(hi)), and megakaryocyte-erythroidprogenitors (MEPs) (Lin⁻/ckit⁺/Sca1⁻/CD34⁺/FcgR^(hi)).

FIGS. 17A-17C. Effects of 22d on p53 targets are p53-dependent. FIG.17A: Change in p53 expression level in 32D-CM cells transduced withpLKO.1 lentivirus expressing sh-p53 or non-silencing control (sh-Ctrl)normalized to levels of b-actin. Shown are mean±SEM. FIG. 17B: Westernblotting of p53 levels in 32D-CM cells expressing sh-p53 or sh-Ctrl.Levels of 3-actin were detected as loading control. FIG. 17C: Foldactivation of p53 target genes treated with 22d (10 mM) for 16 h,determined by qRT-PCR. Relative expression of each target gene wasnormalized to levels of ACTB. * P<0.05.

FIGS. 18A-18F. Treatment of HDAC8i 22d does not affect normal HSCengraftment. Engraftment of normal CB CD34⁺ cells treated with 22d (10μM) or vehicle for 48 h into sub-lethally irradiatedNOD/SCID/interleukin-2 receptor-g chain deficient (NSG) mice. Shown areengraftment levels of each population (CD45+, CD34+, CD33+, CD14+,CD15+) in the bone marrow and spleen weight at 16 weeks aftertransplantation. Each dot represents result from an individual mouse andline indicates medium. ns, not significant. FIGS. 18A-18F (in order):CD45+, CD34+, CD33+, CD14+, CD15+, and spleen.

FIG. 19 CBFb-SMMHC does not affect HDAC8 expression. Western blotanalysis of HDAC8 in 32D-CM or 32D-CBFβ cells before and at various timepoints after IR (3 Gy). Levels of β-actin serve as loading control.

FIG. 20. HDAC8i selectively induce acetylated p53 in CM-expressingcells. Western blot analysis of Ac-p53, p53, acetylated histone H4(Ac-H4) in 32D-CM cells treated with indicated inhibitors. Levels ofβ-actin serve as loading control.

FIGS. 21A-21D. HDAC8 inhibition activates p53 and induces p53-dependentapoptosis in human AML cells. FIG. 21A: Relative survival of human AMLcells treated with HDAC8i (Cmpd 22d) for 48 h, as determined by AnnexinV labeling and normalized to vehicle-treated controls. FIG. 21B: Westernblot analysis of Ac-p53, total p53, Ac-H3, Ac-H4, β-actin in MV4-11cells treated with indicated doses of HDAC8i for 6 h. FIG. 21C: Foldchange in mRNA levels of p53 targets after treatment with PCI-48012 (10mM or 20 mM) for 16 h. FIG. 21D: Western blot analysis of p53, β-actinin MV4-11 cells transduced with control or sh-p53 (top). Relativesurvival of control or sh-p53 transduced MV4-11 cells treated withHDAC8i (bottom).

FIGS. 22A-22E. Activity of HDAC8i compounds on AML cell proliferationand survival. FIGS. 22A-22C. Relative survival of non-p53-mutated AMLcell lines (Mv4-11, MOLM13, OCI-AML3; FIGS. 22A-22C, respectively)treated with various HDAC8i (22d, 5b, 5e, 5 h) for 48 h, as determinedby Annexin V labeling and normalized to vehicle-treated controls. FIGS.22D-22E: Relative proliferation of AML cell lines (Mv4-11, MOLM13, FIGS.22D,22E, respectively) treated with various HDAC8i (22d, 5b, 5e, 5h) for48 h, as determined by Cell Titer-Glo Luminescent Cell Viability Assayand normalized to vehicle treated controls.

FIG. 23. Figure depicts histogram of survival rate of PBSC and CB cellsshowing no significant difference based on cell origin upon contact withCmpd 22d.

FIGS. 24A-24B. Histograms demonstrating no significant changes in p53mRNA or protein levels by CBFβ-SMMHC expression in 32D myeloidprogenitor cell line (FIG. 24A) or in primary myeloid progenitor cells(FIG. 24B). Legend: y-axis: relative expression of indicated proteins.Legend (FIG. 24B): Control (filled), pre-leukemic (open).

FIG. 25. The figure depicts the effect of agents PCI-24781, PCI-48012and Nutlin on protein expression for Ac-p53, p53 and β-actin.

FIGS. 26A-26C. Effects of HDAC8 inhibitors on interaction between p53and CM. FIG. 26A: Figure depicts effects of Cmpd 22d on IgG and IPexpression. FIG. 26B: Figure depicts protein expression levels aftercontact with Cmpd 22d on Ac-p53, p53 and Jβ-actin under the indicatedtiming and wash conditions. FIG. 26C: Histogram depicting survival ratewith and without wash of Cmpd 22d.

FIGS. 27A-27B. Inhibition of HDAC8 selectively activate p53 in inv(16)+AML CD34+ cells. FIG. 27A: Figure depicts Western blotting of Ac-p53,(K382), and p53 levels in inv(16)+ AML CD34+ cells upon contact withCmpd 22d. FIG. 27B: Histogram depicts the fold activation of theindicated p53 target genes (in order left to right: p21, hdm2, 14-3-3σ,puma) in inv(16)+ AML CD34+ and normal CD34+ cells. Legend: inv(16)+ AMLCD34+ (black filled); normal CD34+ cells (gray filled).

DETAILED DESCRIPTION

The abbreviations used herein have their conventional meaning within thechemical and biological arts. The chemical structures and formulae setforth herein are constructed according to the standard rules of chemicalvalency known in the chemical arts.

Where substituent groups are specified by their conventional chemicalformulae, written from left to right, they equally encompass thechemically identical substituents that would result from writing thestructure from right to left, e.g., —CH₂O— is equivalent to —OCH₂—.

The term “alkyl,” by itself or as part of another substituent, means,unless otherwise stated, a straight (i.e., unbranched) or branchedchain, or combination thereof, which may be fully saturated, mono- orpolyunsaturated and can include di- and multivalent radicals, having thenumber of carbon atoms designated (i.e., C₁-C₁₀ means one to tencarbons). Alkyl is not cyclized. Examples of saturated hydrocarbonradicals include, but are not limited to, groups such as methyl, ethyl,n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl,(cyclohexyl)methyl, homologs and isomers of, for example, n-pentyl,n-hexyl, n-heptyl, n-octyl, and the like. An unsaturated alkyl group isone having one or more double bonds or triple bonds. Examples ofunsaturated alkyl groups include, but are not limited to, vinyl,2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl,3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and thehigher homologs and isomers. An alkoxy is an alkyl attached to theremainder of the molecule via an oxygen linker (—O—).

The term “alkylene,” by itself or as part of another substituent, means,unless otherwise stated, a divalent radical derived from an alkyl, asexemplified, but not limited by, —CH₂CH₂CH₂CH₂—. Typically, an alkyl (oralkylene) group will have from 1 to 24 carbon atoms. A “lower alkyl” or“lower alkylene” is a shorter chain alkyl or alkylene group, generallyhaving eight or fewer carbon atoms.

The term “heteroalkyl,” by itself or in combination with another term,means, unless otherwise stated, a stable straight or branched chain, orcombinations thereof, consisting of at least one carbon atom and atleast one heteroatom selected from the group consisting of O, N, P, S,Se and Si, and wherein the nitrogen, selenium, and sulfur atoms mayoptionally be oxidized, and the nitrogen heteroatom may optionally bequaternized. Heteroalkyl is not cyclized. The heteroatom(s) O, N, P, S,Se, and Si may be placed at any interior position of the heteroalkylgroup or at the position at which the alkyl group is attached to theremainder of the molecule. Examples include, but are not limited to:—CH₂—CH₂—O—CH₃, —CH₂—CH₂—NH—CH₃, —CH₂—CH₂—N(CH₃)—CH₃, —CH₂—S—CH₂—CH₃,—CH₂—CH₂, —S(O)—CH₃, —CH₂—CH₂—S(O)₂—CH₃, —CH═CH—O—CH₃, —Si(CH₃)₃,—CH₂—CH═N—OCH₃, —CH═CH—N(CH₃)—CH₃, —O—CH₃, —O—CH₂—CH₃, and —CN. Up totwo heteroatoms may be consecutive, such as, for example, —CH₂—NH—OCH₃.

Similarly, the term “heteroalkylene,” by itself or as part of anothersubstituent, means, unless otherwise stated, a divalent radical derivedfrom heteroalkyl, as exemplified, but not limited by,—CH₂—CH₂—S—CH₂—CH₂— and —CH₂—S—CH₂—CH₂—NH—CH₂—. For heteroalkylenegroups, heteroatoms can also occupy either or both of the chain termini(e.g., alkyleneoxy, alkylenedioxy, alkyleneamino, alkylenediamino, andthe like). Still further, for alkylene and heteroalkylene linkinggroups, no orientation of the linking group is implied by the directionin which the formula of the linking group is written. For example, theformula —C(O)₂R′— represents both —C(O)₂R′— and —R′C(O)₂—. As describedabove, heteroalkyl groups, as used herein, include those groups that areattached to the remainder of the molecule through a heteroatom, such as—C(O)R′, —C(O)NR′, —NR′R″, —OR′, —SeR′, —SR′, and/or —SO₂R′. Where“heteroalkyl” is recited, followed by recitations of specificheteroalkyl groups, such as —NR′R″ or the like, it will be understoodthat the terms heteroalkyl and —NR′R″ are not redundant or mutuallyexclusive. Rather, the specific heteroalkyl groups are recited to addclarity. Thus, the term “heteroalkyl” should not be interpreted hereinas excluding specific heteroalkyl groups, such as —NR′R″ or the like.

The terms “cycloalkyl” and “heterocycloalkyl,” by themselves or incombination with other terms, mean, unless otherwise stated, cyclicversions of“alkyl” and “heteroalkyl,” respectively. Cycloalkyl andheterocycloalkyl are not aromatic. Additionally, for heterocycloalkyl, aheteroatom can occupy the position at which the heterocycle is attachedto the remainder of the molecule. Examples of cycloalkyl include, butare not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like. Examples ofheterocycloalkyl include, but are not limited to,1-(1,2,5,6-tetrahydropyridyl), 1-piperidinyl, 2-piperidinyl,3-piperidinyl, 4-morpholinyl, 3-morpholinyl, tetrahydrofuran-2-yl,tetrahydrofuran-3-yl, tetrahydrothien-2-yl, tetrahydrothien-3-yl,1-piperazinyl, 2-piperazinyl, and the like. A “cycloalkylene” and a“heterocycloalkylene,” alone or as part of another substituent, means adivalent radical derived from a cycloalkyl and heterocycloalkyl,respectively.

The term “aryl” means, unless otherwise stated, a polyunsaturated,aromatic, hydrocarbon substituent, which can be a single ring ormultiple rings (e.g. 1 to 3 rings) that are fused together (i.e., afused ring aryl) or linked covalently. A fused ring aryl refers tomultiple rings fused together wherein at least one of the fused rings isan aryl ring. The term “heteroaryl” refers to aryl groups (or rings)that contain at least one heteroatom (e.g. N, O, or S), wherein sulfurheteroatoms are optionally oxidized, and the nitrogen heteroatoms areoptionally quaternized. Thus, the term “heteroaryl” includes fused ringheteroaryl groups (i.e., multiple rings fused together wherein at leastone of the fused rings is a heteroaromatic ring). A 5,6-fused ringheteroarylene refers to two rings fused together, wherein one ring has 5members and the other ring has 6 members, and wherein at least one ringis a heteroaryl ring. Likewise, a 6,6-fused ring heteroarylene refers totwo rings fused together, wherein one ring has 6 members and the otherring has 6 members, and wherein at least one ring is a heteroaryl ring.And a 6,5-fused ring heteroarylene refers to two rings fused together,wherein one ring has 6 members and the other ring has 5 members, andwherein at least one ring is a heteroaryl ring. A heteroaryl group canbe attached to the remainder of the molecule through a carbon orheteroatom. Non-limiting examples of aryl and heteroaryl groups includephenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl, 1-pyrrolyl, 2-pyrrolyl,3-pyrrolyl, 3-pyrazolyl, 2-imidazolyl, 4-imidazolyl, pyrazinyl,2-oxazolyl, 4-oxazolyl, 2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isoxazolyl,4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl,2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl,2-pyrimidyl, 4-pyrimidyl, 5-benzothiazolyl, purinyl, 2-benzimidazolyl,5-indolyl, 1-isoquinolyl, 5-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl,3-quinolyl, and 6-quinolyl. Substituents for each of the above notedaryl and heteroaryl ring systems are selected from the group ofacceptable substituents described below. An “arylene” and a“heteroarylene,” alone or as part of another substituent, mean adivalent radical derived from an aryl and heteroaryl, respectively.

A fused ring heterocycloalkyl-aryl is an aryl fused to aheterocycloalkyl. A fused ring heterocycloalkyl-heteroaryl is aheteroaryl fused to a heterocycloalkyl. A fused ringheterocycloalkyl-cycloalkyl is a heterocycloalkyl fused to a cycloalkyl.A fused ring heterocycloalkyl-heterocycloalkyl is a heterocycloalkylfused to another heterocycloalkyl. Fused ring heterocycloalkyl-aryl,fused ring heterocycloalkyl-heteroaryl, fused ringheterocycloalkyl-cycloalkyl, or fused ringheterocycloalkyl-heterocycloalkyl may each independently beunsubstituted or substituted with one or more of the substituentsdescribed herein. Spirocyclic rings are two or more rings whereinadjacent rings are attached through a single atom. The individual ringswithin spirocyclic rings may be identical or different. Individual ringsin spirocyclic rings may be substituted or unsubstituted and may havedifferent substituents from other individual rings within a set ofspirocyclic rings. Possible substituents for individual rings withinspirocyclic rings are the possible substituents for the same ring whennot part of spirocyclic rings (e.g. substituents for cycloalkyl orheterocycloalkyl rings). Spirocylic rings may be substituted orunsubstituted cycloalkyl, substituted or unsubstituted cycloalkylene,substituted or unsubstituted heterocycloalkyl or substituted orunsubstituted heterocycloalkylene and individual rings within aspirocyclic ring group may be any of the immediately previous list,including having all rings of one type (e.g. all rings being substitutedheterocycloalkylene wherein each ring may be the same or differentsubstituted heterocycloalkylene). When referring to a spirocyclic ringsystem, heterocyclic spirocyclic rings means a spirocyclic rings whereinat least one ring is a heterocyclic ring and wherein each ring may be adifferent ring. When referring to a spirocyclic ring system, substitutedspirocyclic rings means that at least one ring is substituted and eachsubstituent may optionally be different.

The terms “halo” or “halogen,” by themselves or as part of anothersubstituent, mean, unless otherwise stated, a fluorine, chlorine,bromine, or iodine atom. Additionally, terms such as “haloalkyl” aremeant to include monohaloalkyl and polyhaloalkyl. For example, the term“halo(C₁-C₄)alkyl” includes, but is not limited to, fluoromethyl,difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, 4-chlorobutyl,3-bromopropyl, and the like.

The term “acyl” means, unless otherwise stated, —C(O)R where R is asubstituted or unsubstituted alkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heteroalkyl, substituted orunsubstituted heterocycloalkyl, substituted or unsubstituted aryl, orsubstituted or unsubstituted heteroaryl.

The term “oxo,” as used herein, means an oxygen that is double bonded toa carbon atom.

Each of the above terms (e.g., “alkyl,” “heteroalkyl,” “aryl,” and“heteroaryl”) includes both substituted and unsubstituted forms of theindicated radical. Preferred substituents for each type of radical areprovided below.

Substituents for the alkyl and heteroalkyl radicals (including thosegroups often referred to as alkylene, alkenyl, heteroalkylene,heteroalkenyl, alkynyl, cycloalkyl, heterocycloalkyl, cycloalkenyl, andheterocycloalkenyl) can be one or more of a variety of groups selectedfrom, but not limited to, —OR′, ═O, ═NR′, ═N—OR′, —NR′R″, —SR′,-halogen, —SiR′R″R′″, —OC(O)R′, —C(O)R′, —CO₂R′, —CONR′R″, —OC(O)NR′R″,—NR″C(O)R′, —NR′—C(O)NR″R′″, —NR″C(O)₂R′, —NR—C(NR′R″R′″)═NR″″,—NR—C(NR′R″)═NR′″, —S(O)R′, —S(O)₂R′, —S(O)₂NR′R″, —NRSO₂R′, —CN, and—NO₂ in a number ranging from zero to (2m′+1), where m′ is the totalnumber of carbon atoms in such radical. R′, R″, R′″, and R″″ eachpreferably independently refer to hydrogen, substituted or unsubstitutedheteroalkyl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted heterocycloalkyl, substituted or unsubstituted aryl (e.g.,aryl substituted with 1-3 halogens), substituted or unsubstituted alkyl,alkoxy, or thioalkoxy groups, or arylalkyl groups. When a compounddescribed herein includes more than one R group, for example, each ofthe R groups is independently selected as are each R′, R″, R′″, and R″″group when more than one of these groups is present. When R′ and R″ areattached to the same nitrogen atom, they can be combined with thenitrogen atom to form a 4-, 5-, 6-, or 7-membered ring. For example,—NR′R″ includes, but is not limited to, 1-pyrrolidinyl and4-morpholinyl. From the above discussion of substituents, one of skillin the art will understand that the term “alkyl” is meant to includegroups including carbon atoms bound to groups other than hydrogengroups, such as haloalkyl (e.g., —CF₃ and —CH₂CF₃) and acyl (e.g.,—C(O)CH₃, —C(O)CF₃, —C(O)CH₂OCH₃, and the like).

Similar to the substituents described for the alkyl radical,substituents for the aryl and heteroaryl groups are varied and areselected from, for example: —OR′, —NR′R″, —SR′, -halogen, —SiR′R″R′″,—OC(O)R′, —C(O)R′, —CO₂R′, —CONR′R″, —OC(O)NR′R″, —NR″C(O)R′,—NR′—C(O)NR″R′″, —NR″C(O)₂R′, —NR—C(NR′R″R′″)═NR″″, —NR—C(NR′R″)═NR′″,—S(O)R′, —S(O)₂R′, —S(O)₂NR′R″, —NRSO₂R′, —CN, —NO₂, —R′, —N₃, —CH(Ph)₂,fluoro(C₁-C₄)alkoxy, and fluoro(C₁-C₄)alkyl, in a number ranging fromzero to the total number of open valences on the aromatic ring system;and where R′, R″, R′″, and R″″ are preferably independently selectedfrom hydrogen, substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, and substituted or unsubstituted heteroaryl. When acompound described herein includes more than one R group, for example,each of the R groups is independently selected as are each R′, R″, R′″,and R″″ groups when more than one of these groups is present.

Substituents for rings (e.g. cycloalkyl, heterocycloalkyl, aryl,heteroaryl, cycloalkylene, heterocycloalkylene, arylene, orheteroarylene) may be depicted as substituents on the ring rather thanon a specific atom of a ring (commonly referred to as a floatingsubstituent). In such a case, the substituent may be attached to any ofthe ring atoms (obeying the rules of chemical valency) and in the caseof fused rings or spirocyclic rings, a substituent depicted asassociated with one member of the fused rings or spirocyclic rings (afloating substituent on a single ring), may be a substituent on any ofthe fused rings or spirocyclic rings (a floating substituent on multiplerings). When a substituent is attached to a ring, but not a specificatom (a floating substituent), and a subscript for the substituent is aninteger greater than one, the multiple substituents may be on the sameatom, same ring, different atoms, different fused rings, differentspirocyclic rings, and each substituent may optionally be different.Where a point of attachment of a ring to the remainder of a molecule isnot limited to a single atom (a floating substituent), the attachmentpoint may be any atom of the ring and in the case of a fused ring orspirocyclic ring, any atom of any of the fused rings or spirocyclicrings while obeying the rules of chemical valency. Where a ring, fusedrings, or spirocyclic rings contain one or more ring heteroatoms and thering, fused rings, or spirocyclic rings are shown with one more floatingsubstituents (including, but not limited to, points of attachment to theremainder of the molecule), the floating substituents may be bonded tothe heteroatoms. Where the ring heteroatoms are shown bound to one ormore hydrogens (e.g. a ring nitrogen with two bonds to ring atoms and athird bond to a hydrogen) in the structure or formula with the floatingsubstituent, when the heteroatom is bonded to the floating substituent,the substituent will be understood to replace the hydrogen, whileobeying the rules of chemical valency.

Two or more substituents may optionally be joined to form aryl,heteroaryl, cycloalkyl, or heterocycloalkyl groups. Such so-calledring-forming substituents are typically, though not necessarily, foundattached to a cyclic base structure. The ring-forming substituents maybe attached to adjacent members of the base structure. For example, tworing-forming substituents attached to adjacent members of a cyclic basestructure create a fused ring structure. The ring-forming substituentsmay be attached to a single member of the base structure. For example,two ring-forming substituents attached to a single member of a cyclicbase structure create a spirocyclic structure. The ring-formingsubstituents may be attached to non-adjacent members of the basestructure.

Two of the substituents on adjacent atoms of the aryl or heteroaryl ringmay optionally form a ring of the formula -T-C(O)—(CRR′)_(q)—U—, whereinT and U are independently —NR—, —O—, —CRR′—, or a single bond, and q isan integer of from 0 to 3. Alternatively, two of the substituents onadjacent atoms of the aryl or heteroaryl ring may optionally be replacedwith a substituent of the formula -A-(CH₂)_(r)—B—, wherein A and B areindependently —CRR′—, —O—, —NR—, —S—, —S(O)—, —S(O)₂—, —S(O)₂NR′—, or asingle bond, and r is an integer of from 1 to 4. One of the single bondsof the new ring so formed may optionally be replaced with a double bond.Alternatively, two of the substituents on adjacent atoms of the aryl orheteroaryl ring may optionally be replaced with a substituent of theformula —(CRR′)_(s)—X′—(C″R′″)_(d)—, where s and d are independentlyintegers of from 0 to 3, and X′ is —O—, —NR′—, —S—, —S(O)—, —S(O)₂—, or—S(O)₂NR′—. The substituents R, R′, R″, and R′″ are preferablyindependently selected from hydrogen, substituted or unsubstitutedalkyl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted heterocycloalkyl, substituted or unsubstituted aryl, andsubstituted or unsubstituted heteroaryl.

As used herein, the terms “heteroatom” or “ring heteroatom” are meant toinclude oxygen (O), nitrogen (N), sulfur (S), phosphorus (P), andsilicon (Si).

A “substituent group,” as used herein, means a group selected from thefollowing moieties:

-   -   (A) —OH, —NH₂, —SH, —CN, —CF₃, —NO₂, oxo, halogen, unsubstituted        alkyl, unsubstituted heteroalkyl, unsubstituted cycloalkyl,        unsubstituted heterocycloalkyl, unsubstituted aryl,        unsubstituted heteroaryl, and    -   (B) alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, and        heteroaryl, substituted with at least one substituent selected        from:        -   (i) oxo, —OH, —NH₂, —SH, —CN, —CF₃, —NO₂, halogen,            unsubstituted alkyl, unsubstituted heteroalkyl,            unsubstituted cycloalkyl, unsubstituted heterocycloalkyl,            unsubstituted aryl, unsubstituted heteroaryl, and        -   (ii) alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl,            and heteroaryl, substituted with at least one substituent            selected from:            -   (a) oxo, —OH, —NH₂, —SH, —CN, —CF₃, —NO₂, halogen,                unsubstituted alkyl, unsubstituted heteroalkyl,                unsubstituted cycloalkyl, unsubstituted                heterocycloalkyl, unsubstituted aryl, unsubstituted                heteroaryl, and            -   (b) alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl,                aryl, or heteroaryl, substituted with at least one                substituent selected from: oxo, —OH, —NH₂, —SH, —CN,                —CF₃, —NO₂, halogen, unsubstituted alkyl, unsubstituted                heteroalkyl, unsubstituted cycloalkyl, unsubstituted                heterocycloalkyl, unsubstituted aryl, and unsubstituted                heteroaryl.

A “size-limited substituent” or “size-limited substituent group,” asused herein, means a group selected from all of the substituentsdescribed above for a “substituent group,” wherein each substituted orunsubstituted alkyl is a substituted or unsubstituted C₁-C₂₀ alkyl, eachsubstituted or unsubstituted heteroalkyl is a substituted orunsubstituted 2 to 20 membered heteroalkyl, each substituted orunsubstituted cycloalkyl is a substituted or unsubstituted C₃-C₈cycloalkyl, each substituted or unsubstituted heterocycloalkyl is asubstituted or unsubstituted 3 to 8 membered heterocycloalkyl, eachsubstituted or unsubstituted aryl is a substituted or unsubstitutedC₃-C₈ aryl, and each substituted or unsubstituted heteroaryl is asubstituted or unsubstituted C₃-C₈₅ heteroaryl.

A “lower substituent” or “lower substituent group,” as used herein,means a group selected from all of the substituents described above fora “substituent group,” wherein each substituted or unsubstituted alkylis a substituted or unsubstituted C₁-C₈ alkyl, each substituted orunsubstituted heteroalkyl is a substituted or unsubstituted 2 to 8membered heteroalkyl, each substituted or unsubstituted cycloalkyl is asubstituted or unsubstituted C₃-C₇ cycloalkyl, each substituted orunsubstituted heterocycloalkyl is a substituted or unsubstituted 3 to 7membered heterocycloalkyl, each substituted or unsubstituted aryl is asubstituted or unsubstituted C₃-C₇ aryl, and each substituted orunsubstituted heteroaryl is a substituted or unsubstituted C₃-C₇heteroaryl.

Each substituted group described in the compounds herein may besubstituted with at least one substituent group. More specifically, eachsubstituted alkyl, substituted heteroalkyl, substituted cycloalkyl,substituted heterocycloalkyl, substituted aryl, substituted heteroaryl,substituted alkylene, substituted heteroalkylene, substitutedcycloalkylene, substituted heterocycloalkylene, substituted arylene,and/or substituted heteroarylene described in the compounds herein maybe substituted with at least one substituent group. At least one or allof these groups may be substituted with at least one size-limitedsubstituent group. At least one or all of these groups may besubstituted with at least one lower substituent group.

Each substituted or unsubstituted alkyl may be a substituted orunsubstituted C₁-C₂₀ alkyl, each substituted or unsubstitutedheteroalkyl is a substituted or unsubstituted 2 to 20 memberedheteroalkyl, each substituted or unsubstituted cycloalkyl may be asubstituted or unsubstituted C₃-C₈ cycloalkyl, and/or each substitutedor unsubstituted heterocycloalkyl may be a substituted or unsubstituted3 to 8 membered heterocycloalkyl. Each substituted or unsubstitutedalkylene may be a substituted or unsubstituted C₁-C₂₀ alkylene, eachsubstituted or unsubstituted heteroalkylene may be a substituted orunsubstituted 2 to 20 membered heteroalkylene, each substituted orunsubstituted cycloalkylene may be a substituted or unsubstituted C₃-C₈cycloalkylene, each substituted or unsubstituted heterocycloalkylene maybe a substituted or unsubstituted 3 to 8 membered heterocycloalkylene,each substituted or unsubstituted arylene may be a substituted orunsubstituted C₃-C₈ arylene, and/or each substituted or unsubstitutedheteroaryl may be a substituted or unsubstituted C₃-C₈ heteroarylene.

Each substituted or unsubstituted alkyl may be a substituted orunsubstituted C₁-C₈ alkyl, each substituted or unsubstituted heteroalkylmay be a substituted or unsubstituted 2 to 8 membered heteroalkyl, eachsubstituted or unsubstituted cycloalkyl may be a substituted orunsubstituted C₃-C₇ cycloalkyl, each substituted or unsubstitutedheterocycloalkyl may be a substituted or unsubstituted 3 to 7 memberedheterocycloalkyl, each substituted or unsubstituted aryl may be asubstituted or unsubstituted C₃-C₇ aryl, and/or each substituted orunsubstituted heteroaryl may be a substituted or unsubstituted C₃-C₇heteroaryl. Each substituted or unsubstituted alkylene may be asubstituted or unsubstituted C₁-C₈ alkylene, each substituted orunsubstituted heteroalkylene may be a substituted or unsubstituted 2 to8 membered heteroalkylene, each substituted or unsubstitutedcycloalkylene may be a substituted or unsubstituted C₃-C₇ cycloalkylene,each substituted or unsubstituted heterocycloalkylene may be asubstituted or unsubstituted 3 to 7 membered heterocycloalkylene, eachsubstituted or unsubstituted arylene may be a substituted orunsubstituted C₃-C₇ arylene, and/or each substituted or unsubstitutedheteroarylene may be a substituted or unsubstituted C₃-C₇ heteroarylene.

Certain compounds described herein possess asymmetric carbon atoms(optical or chiral centers) or double bonds; the enantiomers, racemates,diastereomers, tautomers, geometric isomers, stereoisomeric forms thatmay be defined, in terms of absolute stereochemistry, as (R)- or (S)-or, as (D)- or (L)- for amino acids, and individual isomers areencompassed within the scope of the compounds described herein. Thecompounds described herein do not include those that are known in art tobe too unstable to synthesize and/or isolate. Compounds described hereininclude compounds in racemic and optically pure forms. Optically active(R)- and (S)-, or (D)- and (L)-isomers may be prepared using chiralsynthons or chiral reagents, or resolved using conventional techniques.When the compounds described herein contain olefinic bonds or othercenters of geometric asymmetry, and unless specified otherwise, it isintended that the compounds include both E and Z geometric isomers.

As used herein, the term “isomers” refers to compounds having the samenumber and kind of atoms, and hence the same molecular weight, butdiffering in respect to the structural arrangement or configuration ofthe atoms.

The term “tautomer,” as used herein, refers to one of two or morestructural isomers which exist in equilibrium and which are readilyconverted from one isomeric form to another.

It will be apparent to one skilled in the art that certain compoundsdescribed herein may exist in tautomeric forms, all such tautomericforms of the compounds being within the scope described herein.

Unless otherwise stated, structures depicted herein are also meant toinclude all stereochemical forms of the structure; i.e., the R and Sconfigurations for each asymmetric center. Therefore, singlestereochemical isomers as well as enantiomeric and diastereomericmixtures of the present compounds are within the scope described herein.

Unless otherwise stated, structures depicted herein are also meant toinclude compounds which differ only in the presence of one or moreisotopically enriched atoms. For example, compounds described hereininclude the present structures except for the replacement of a hydrogenby a deuterium or tritium, or the replacement of a carbon by ¹³C- or¹⁴C-enriched carbon.

The compounds described herein may also contain unnatural proportions ofatomic isotopes at one or more of the atoms that constitute suchcompounds. For example, the compounds may be radiolabeled withradioactive isotopes, such as for example tritium (³H), iodine-125(¹²⁵I), or carbon-14 (¹⁴C). Compounds described herein further includeall isotopic variations thereof, whether radioactive or not.

The symbol “

” denotes the point of attachment of a chemical moiety to the remainderof a molecule or chemical formula.

“Analog” or “analogue” is used in accordance with its plain ordinarymeaning within Chemistry and Biology and refers to a chemical compoundthat is structurally similar to another compound (i.e., a so-called“reference” compound) but differs in composition, e.g., in thereplacement of one atom by an atom of a different element, or in thepresence of a particular functional group, or the replacement of onefunctional group by another functional group, or the absolutestereochemistry of one or more chiral centers of the reference compound.Accordingly, an analog is a compound that is similar or comparable infunction and appearance but not in structure or origin to a referencecompound.

The terms “a” or “an,” as used in herein means one or more. In addition,the phrase “substituted with a[n],” as used herein, means the specifiedgroup may be substituted with one or more of any or all of the namedsubstituents. For example, where a group, such as an alkyl or heteroarylgroup, is “substituted with an unsubstituted C₁-C₂₀ alkyl, orunsubstituted 2 to 20 membered heteroalkyl,” the group may contain oneor more unsubstituted C₁-C₂₀ alkyls, and/or one or more unsubstituted 2to 20 membered heteroalkyls.

Moreover, where a moiety is substituted with an R substituent, the groupmay be referred to as “R-substituted.” Where a moiety is R-substituted,the moiety is substituted with at least one R substituent and each Rsubstituent is optionally different. Where a particular R group ispresent in the description of a chemical genus (such as Formula (I)), adecimal symbol may be used to distinguish each appearance of thatparticular R group. For example, where multiple R¹³ substituents arepresent, each R¹³ substituent may be distinguished as R^(13.1),R^(13.2), R^(13.3), R^(13.4), etc., wherein each of R^(13.1), R^(13.2),R^(13.3), R^(13.4), etc. is defined within the scope of the definitionof R¹³ and optionally differently.

Description of compounds described herein are limited by principles ofchemical bonding known to those skilled in the art. Accordingly, where agroup may be substituted by one or more of a number of substituents,such substitutions are selected so as to comply with principles ofchemical bonding and to give compounds which are not inherently unstableand/or would be known to one of ordinary skill in the art as likely tobe unstable under ambient conditions, such as aqueous, neutral, andseveral known physiological conditions. For example, a heterocycloalkylor heteroaryl is attached to the remainder of the molecule via a ringheteroatom in compliance with principles of chemical bonding known tothose skilled in the art thereby avoiding inherently unstable compounds.

The terms “DNA” and “RNA” refer to deoxyribonucleic acid and ribonucleicacid, respectively.

“Nucleic acid” refers to deoxyribonucleotides or ribonucleotides andpolymers thereof in either single- or double-stranded form, andcomplements thereof. The term “polynucleotide” refers to a linearsequence of nucleotides. The term “nucleotide” typically refers to asingle unit of a polynucleotide, i.e., a monomer. Nucleotides can beribonucleotides, deoxyribonucleotides, or modified versions thereof.Examples of polynucleotides contemplated herein include single anddouble stranded DNA, single and double stranded RNA (including siRNA),and hybrid molecules having mixtures of single and double stranded DNAand RNA. Nucleic acid as used herein also refers nucleic acids that havethe same basic chemical structure as naturally occurring nucleic acids.Such analogues have modified sugars and/or modified ring substituents,but retain the same basic chemical structure as the naturally occurringnucleic acid. A nucleic acid mimetic refers to chemical compounds thathave a structure that is different the general chemical structure of anucleic acid, but functions in a manner similar to a naturally occurringnucleic acid. Examples of such analogues include, without limitation,phosphorothioates, phosphoramidates, methyl phosphonates, chiral-methylphosphonates, 2-O-methyl ribonucleotides, and peptide-nucleic acids(PNAs).

“Synthetic mRNA” as used herein refers to any mRNA derived throughnon-natural means such as standard oligonucleotide synthesis techniquesor cloning techniques. Such mRNA may also include non-proteinogenicderivatives of naturally occurring nucleotides. Additionally, “syntheticmRNA” herein also includes mRNA that has been expressed throughrecombinant techniques or exogenously, using any expression vehicle,including but not limited to prokaryotic cells, eukaryotic cell lines,and viral methods. “Synthetic mRNA” includes such mRNA that has beenpurified or otherwise obtained from an expression vehicle or system.

The terms “polypeptide,” “peptide” and “protein” are usedinterchangeably herein to refer to a polymer of amino acid residues,wherein the polymer may optionally be conjugated to a moiety that doesnot consist of amino acids. The terms apply to amino acid polymers inwhich one or more amino acid residue is an artificial chemical mimeticof a corresponding naturally occurring amino acid, as well as tonaturally occurring amino acid polymers and non-naturally occurringamino acid polymer.

The term “peptidyl” and “peptidyl moiety” means a monovalent peptide.

The term “amino acid” refers to naturally occurring and synthetic aminoacids, as well as amino acid analogs and amino acid mimetics thatfunction in a manner similar to the naturally occurring amino acids.Naturally occurring amino acids are those encoded by the genetic code,as well as those amino acids that are later modified, e.g.,hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. Amino acidanalogs refers to compounds that have the same basic chemical structureas a naturally occurring amino acid, i.e., an a carbon that is bound toa hydrogen, a carboxyl group, an amino group, and an R group, e.g.,homoserine, norleucine, methionine sulfoxide, methionine methylsulfonium. Such analogs have modified R groups (e.g., norleucine) ormodified peptide backbones, but retain the same basic chemical structureas a naturally occurring amino acid. Amino acid mimetics refers tochemical compounds that have a structure that is different from thegeneral chemical structure of an amino acid, but that functions in amanner similar to a naturally occurring amino acid.

Amino acids may be referred to herein by either their commonly knownthree letter symbols or by the one-letter symbols recommended by theIUPAC-IUB Biochemical Nomenclature Commission. Nucleotides, likewise,may be referred to by their commonly accepted single-letter codes.

“Conservatively modified variants” applies to both amino acid andnucleic acid sequences. With respect to particular nucleic acidsequences, conservatively modified variants refers to those nucleicacids which encode identical or essentially identical amino acidsequences, or where the nucleic acid does not encode an amino acidsequence, to essentially identical sequences. Because of the degeneracyof the genetic code, a large number of functionally identical nucleicacids encode any given protein. For instance, the codons GCA, GCC, GCGand GCU all encode the amino acid alanine. Thus, at every position wherean alanine is specified by a codon, the codon can be altered to any ofthe corresponding codons described without altering the encodedpolypeptide. Such nucleic acid variations are “silent variations,” whichare one species of conservatively modified variations. Every nucleicacid sequence herein which encodes a polypeptide also describes everypossible silent variation of the nucleic acid. One of skill willrecognize that each codon in a nucleic acid (except AUG, which isordinarily the only codon for methionine, and TGG, which is ordinarilythe only codon for tryptophan) can be modified to yield a functionallyidentical molecule. Accordingly, each silent variation of a nucleicacid, which encodes a polypeptide, is implicit in each describedsequence with respect to the expression product, but not with respect toactual probe sequences.

As to amino acid sequences, one of skill will recognize that individualsubstitutions, deletions or additions to a nucleic acid, peptide,polypeptide, or protein sequence which alters, adds or deletes a singleamino acid or a small percentage of amino acids in the encoded sequenceis a “conservatively modified variant” where the alteration results inthe substitution of an amino acid with a chemically similar amino acid.Conservative substitution tables providing functionally similar aminoacids are well known in the art. Such conservatively modified variantsare in addition to and do not exclude polymorphic variants, interspecieshomologs, and alleles described herein.

The following eight groups each contain amino acids that areconservative substitutions for one another: 1) Alanine (A), Glycine (G);2) Aspartic acid (D), Glutamic acid (E); 3) Asparagine (N), Glutamine(Q); 4) Arginine (R), Lysine (K); 5) Isoleucine (I), Leucine (L),Methionine (M), Valine (V); 6) Phenylalanine (F), Tyrosine (Y),Tryptophan (W); 7) Serine (S), Threonine (T); and 8) Cysteine (C),Methionine (M) (see. e.g., Creighton, Proteins (1984)).

The term “pharmaceutically acceptable salts” is meant to include saltsof the active compounds that are prepared with relatively nontoxic acidsor bases, depending on the particular substituents found on thecompounds described herein. When compounds described herein containrelatively acidic functionalities, base addition salts can be obtainedby contacting the neutral form of such compounds with a sufficientamount of the desired base, either neat or in a suitable inert solvent.Examples of pharmaceutically acceptable base addition salts includesodium, potassium, calcium, ammonium, organic amino, or magnesium salt,or a similar salt. When compounds described herein contain relativelybasic functionalities, acid addition salts can be obtained by contactingthe neutral form of such compounds with a sufficient amount of thedesired acid, either neat or in a suitable inert solvent. Examples ofpharmaceutically acceptable acid addition salts include those derivedfrom inorganic acids like hydrochloric, hydrobromic, nitric, carbonic,monohydrogencarbonic, phosphoric, monohydrogenphosphoric,dihydrogenphosphoric, sulfuric, monohydrogensulfiuric, hydriodic, orphosphorous acids and the like, as well as the salts derived fromrelatively nontoxic organic acids like acetic, propionic, isobutyric,maleic, malonic, benzoic, succinic, suberic, fumaric, lactic, mandelic,phthalic, benzenesulfonic, p-tolylsulfonic, citric, tartaric, oxalic,methanesulfonic, and the like. Also included are salts of amino acidssuch as arginate and the like, and salts of organic acids likeglucuronic or galactunoric acids and the like (see, for example, Bergeet al., “Pharmaceutical Salts”, Journal of Pharmaceutical Science, 1977,66, 1-19). Certain specific compounds described herein contain bothbasic and acidic functionalities that allow the compounds to beconverted into either base or acid addition salts.

Thus, the compounds described herein may exist as salts, such as withpharmaceutically acceptable acids. The compounds described hereininclude such salts. Non-limiting examples of such salts includehydrochlorides, hydrobromides, phosphates, sulfates, methanesulfonates,nitrates, maleates, acetates, citrates, fumarates, propionates,tartrates (e.g., (+)-tartrates, (−)-tartrates, or mixtures thereofincluding racemic mixtures), succinates, benzoates, and salts with aminoacids such as glutamic acid, and quaternary ammonium salts (e.g. methyliodide, ethyl iodide, and the like). These salts may be prepared bymethods known to those skilled in the art.

The neutral forms of the compounds are preferably regenerated bycontacting the salt with a base or acid and isolating the parentcompound in the conventional manner. The parent form of the compound maydiffer from the various salt forms in certain physical properties, suchas solubility in polar solvents.

In addition to salt forms, the compounds described herein may beprovided in a prodrug form. Prodrugs of the compounds described hereinare those compounds that readily undergo chemical changes underphysiological conditions to provide their respective active forms.Prodrugs of the compounds described herein may be converted in vivoafter administration. Additionally, prodrugs can be converted to thecompounds described herein by chemical or biochemical methods in an exvivo environment, such as, for example, when contacted with a suitableenzyme or chemical reagent.

Certain compounds described herein can exist in unsolvated forms as wellas solvated forms, including hydrated forms. In general, the solvatedforms compounds described herein are equivalent to unsolvated forms.Certain compounds described herein may exist in multiple crystalline oramorphous forms. In general, all physical forms compounds describedherein are equivalent for their uses described herein.

“Pharmaceutically acceptable excipient” and “pharmaceutically acceptablecarrier” refer to a substance that aids the administration of an activeagent to and absorption by a subject and can be included in thecompositions described herein without causing a significant adversetoxicological effect on the patient. Non-limiting examples ofpharmaceutically acceptable excipients include water, NaCl, normalsaline solutions, lactated Ringer's, normal sucrose, normal glucose,binders, fillers, disintegrants, lubricants, coatings, sweeteners,flavors, salt solutions (such as Ringer's solution), alcohols, oils,gelatins, carbohydrates such as lactose, amylose or starch, fatty acidesters, hydroxymethylcellulose, polyvinyl pyrrolidine, and colors, andthe like. Such preparations can be sterilized and, if desired, mixedwith auxiliary agents such as lubricants, preservatives, stabilizers,wetting agents, emulsifiers, salts for influencing osmotic pressure,buffers, coloring, and/or aromatic substances and the like that do notdeleteriously react with the compounds described herein. One of skill inthe art will recognize that other pharmaceutical excipients are usefulin the compositions described herein.

The term “preparation” is intended to include the formulation of theactive compound with encapsulating material as a carrier providing acapsule in which the active component with or without other carriers, issurrounded by a carrier, which is thus in association with it.Similarly, cachets and lozenges are included. Tablets, powders,capsules, pills, cachets, and lozenges can be used as solid dosage formssuitable for oral administration.

As used herein, the term “administering” means oral administration,administration as a suppository, topical contact, intravenous,parenteral, intraperitoneal, intramuscular, intralesional, intrathecal,intranasal or subcutaneous administration, or the implantation of aslow-release device, e.g., a mini-osmotic pump, to a subject.Administration is by any route, including parenteral and transmucosal(e.g., buccal, sublingual, palatal, gingival, nasal, vaginal, rectal, ortransdermal). Parenteral administration includes, e.g., intravenous,intramuscular, intra-arteriole, intradermal, subcutaneous,intraperitoneal, intraventricular, and intracranial. Other modes ofdelivery include, but are not limited to, the use of liposomalformulations, intravenous infusion, transdermal patches, etc.

The compositions disclosed herein can be delivered by transdermally, bya topical route, formulated as applicator sticks, solutions,suspensions, emulsions, gels, creams, ointments, pastes, jellies,paints, powders, and aerosols. Oral preparations include tablets, pills,powder, dragees, capsules, liquids, lozenges, cachets, gels, syrups,slurries, suspensions, etc., suitable for ingestion by the patient.Solid form preparations include powders, tablets, pills, capsules,cachets, suppositories, and dispersible granules. Liquid formpreparations include solutions, suspensions, and emulsions, for example,water or water/propylene glycol solutions. The compositions of thepresent invention may additionally include components to providesustained release and/or comfort. Such components include high molecularweight, anionic mucomimetic polymers, gelling polysaccharides andfinely-divided drug carrier substrates. These components are discussedin greater detail in U.S. Pat. Nos. 4,911,920; 5,403,841; 5,212,162; and4,861,760. The entire contents of these patents are incorporated hereinby reference in their entirety for all purposes. The compositionsdisclosed herein can also be delivered as microspheres for slow releasein the body. For example, microspheres can be administered viaintradermal injection of drug-containing microspheres, which slowlyrelease subcutaneously (see Rao, J. Biomater Sci. Polym. Ed. 7:623-645,1995; as biodegradable and injectable gel formulations (see, e.g., GaoPharm. Res. 12:857-863, 1995); or, as microspheres for oraladministration (see, e.g., Eyles, J. Pharm. Pharmacol. 49:669-674,1997). In another embodiment, the formulations of the compositions ofthe present invention can be delivered by the use of liposomes whichfuse with the cellular membrane or are endocytosed, i.e., by employingreceptor ligands attached to the liposome, that bind to surface membraneprotein receptors of the cell resulting in endocytosis. By usingliposomes, particularly where the liposome surface carries receptorligands specific for target cells, or are otherwise preferentiallydirected to a specific organ, one can focus the delivery of thecompositions of the present invention into the target cells in vivo.(See, e.g., Al-Muhammed, J. Microencapsul. 13:293-306, 1996; Chonn,Curr. Opin. Biotechnol. 6:698-708, 1995; Ostro, Am. J. Hosp. Pharm.46:1576-1587, 1989). The compositions can also be delivered asnanoparticles.

Pharmaceutical compositions may include compositions wherein the activeingredient (e.g. compounds described herein, including embodiments orexamples) is contained in a therapeutically effective amount, i.e., inan amount effective to achieve its intended purpose. The actual amounteffective for a particular application will depend, inter alia. on thecondition being treated. When administered in methods to treat adisease, such compositions will contain an amount of active ingredienteffective to achieve the desired result, e.g., modulating the activityof a target molecule, and/or reducing, eliminating, or slowing theprogression of disease symptoms.

The dosage and frequency (single or multiple doses) administered to amammal can vary depending upon a variety of factors, for example,whether the mammal suffers from another disease, and its route ofadministration; size, age, sex, health, body weight, body mass index,and diet of the recipient; nature and extent of symptoms of the diseasebeing treated, kind of concurrent treatment, complications from thedisease being treated or other health-related problems. Othertherapeutic regimens or agents can be used in conjunction with themethods and compounds of Applicants' invention. Adjustment andmanipulation of established dosages (e.g., frequency and duration) arewell within the ability of those skilled in the art.

The compounds and complexes described herein can be used in combinationwith one another, with other active drugs known to be useful in treatinga disease (e.g. anti-cancer drugs) or with adjunctive agents that maynot be effective alone, but may contribute to the efficacy of the activeagent.

By “co-administer” it is meant that a composition described herein isadministered at the same time, just prior to, or just after theadministration of one or more additional therapies, for example ananticancer agent as described herein. The compound of the invention canbe administered alone or can be co-administered to the patient.Co-administration is meant to include simultaneous or sequentialadministration of the compound individually or in combination (more thanone compound or agent). Thus, the preparations can also be combined,when desired, with other active substances (e.g. anticancer agents).

Co-administration includes administering one active agent (e.g. acomplex described herein) within 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, or24 hours of a second active agent (e.g. anti-cancer agents). Alsocontemplated herein, are embodiments, where co-administration includesadministering one active agent within 0.5, 1, 2, 4, 6, 8, 10, 12, 16,20, or 24 hours of a second active agent. Co-administration includesadministering two active agents simultaneously, approximatelysimultaneously (e.g., within about 1, 5, 10, 15, 20, or 30 minutes ofeach other), or sequentially in any order. In embodiments,co-administration can be accomplished by co-formulation, i.e., preparinga single pharmaceutical composition including both active agents. Inother embodiments, the active agents can be formulated separately. Inembodiments, the active and/or adjunctive agents may be linked orconjugated to one another. In embodiments, the compounds and complexesdescribed herein may be combined with treatments for cancer such aschemotherapy or radiation therapy.

The terms “HDAC8 inhibitor” and “HDAC8i” are used interchangeably hereinand refer a composition (e.g. compound, peptide, protein, nucleic acid,or antibody) which reduces the activity of HDAC8 (Histone Deacetylase 8)relative to the activity of HDAC8 in the absence of the inhibitor. HDAC8inhibitors may be selective for HDAC8 as described herein. The HDAC8inhibitor may be a HDAC8 inhibitor compound (e.g. a compound having amolecular weight (MW) of less than about 1000 Da). The HDAC8 inhibitorcompound may be a compound described herein. HDAC8 inhibitor compoundsfurther include compounds known to selectively inhibit HDAC8 expressionor activity including one or more of those exemplified in, for example,U.S. Pat. No. 7,820,711; PCT/JP2011/050647; and/or PCT/US2014/012968.

HDAC8 inhibitor compounds include one or more of the compounds describedherein, and further includes, for example, one or more of the compoundsdescribed by K. Krennhrubec, et al., Bioorg. Med. Chem. Lett. 2007, 17,2874-2878; P. Galletti, et al., ChemMedChem. 2009, 4, 1991-2001; E. Hu,et al., J. Pharmacol. Exp. Ther. 2003, 307, 720-728; W. Tang, et al.,Bioorg. Med. Chem. Lett. 2011, 21, 2601-2605; S. Balasubramanian, etal., Leukemia 2008, 22, 1026-1034; L. Whitehead, et al., Bioorg. Med.Chem. 2011, 19, 4626-4634; and T. Suzuki, et al., ChemMedChem. 2014, 9,657-664.

The HDAC8 inhibitor may be a HDAC8 inhibitor antibody (e.g. thosedescribed by PCT/US2000/033622). The HDAC8 inhibitor may be a HDAC8inhibitor polynucleotide. The HDAC8 inhibitor polynucleotide may be amdRNA as described by, for example, PCT/US2008/055612. The HDAC8inhibitor polynucleotide may be RNA (e.g. a HDAC8 inhibitor RNA), siRNA(e.g. a HDAC8 inhibitor siRNA), shRNA (e.g. a HDAC8 inhibitor shRNA) ora miRNA (e.g. a HDAC8 inhibitor miRNA). The HDAC8 inhibitor may be aHDAC8 inhibitor protein.

“Selective”, “selectivity” or the like of a compound refers to thecompound's ability to discriminate between molecular targets. Aselective HDAC8 inhibitor described herein may have an IC₅₀ for HDAC8activity that is at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 foldlower than the IC₅₀ for one or more of HDAC1, HDAC2, HDAC3, HDAC6,HDAC10, and/or HDAC 11. A selective HDAC8 inhibitor may have an IC₅₀ forHDAC8 acetyltransferase activity that is about 5, 10, 50, 150, 200, 250,300, 350, 400, 450 or more than about 500 fold lower than the IC₅₀ foracetyltransferase activity of another HDAC (e.g. HDAC1, HDAC2, HDAC3,HDAC6, HDAC10, or HDAC 11).

“Specific”, “specifically”, “specificity”, or the like of a compoundrefers to the compound's ability to cause a particular action, such asinhibition, to a particular molecular target with minimal or no actionto other proteins in the cell.

“HDAC8” is used herein and according to its common, ordinary meaning andrefers to proteins of the same or similar names and functional fragmentsand homologs thereof. The term includes any recombinant or naturallyoccurring form of HDAC8 (e.g. Histone deacetylase 8; GI No: 8132878), orvariants or fragments thereof that maintain HDAC8 activity (e.g. withinat least 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 100% activitycompared to HDAC8).

“p53” is used herein and according to its common, ordinary meaning andrefers to proteins of the same or similar names and functional fragmentsand homologs thereof. The term includes any recombinant or naturallyoccurring form of p53 (e.g. GI No: 23491729), or variants or fragmentsthereof that maintain p53 activity (e.g. within at least 30%, 40%, 50%,60%, 70%, 80%, 90%, 95%, or 100% activity compared to p53). A “mutatedp53” is a p53 variant that is aberrantly acetylated or deacetylatedresulting from a mutation to the wildtype p53 amino acid sequence. Thephrase “non-mutated p53” refers to p53 variants which are correctlyacetylated or deacetylated. A non-mutated p53 may include mutations solong as those mutations impart no effect on p53 acetylation ordeacetylation. Thus, a “non-mutated p53 cancer” refers to a cancercharacterized by correctly acetylated or deacetylated p53. Likewise, a“mutated p53 cancer” refers to a cancer characterized by incorrectlyacetylated or deacetylated p53.

The terms “treating”, or “treatment” refers to any indicia of success inthe treatment or amelioration of an injury, disease, pathology orcondition, including any objective or subjective parameter such asabatement; remission; diminishing of symptoms or making the injury,pathology or condition more tolerable to the patient; slowing in therate of degeneration or decline; making the final point of degenerationless debilitating; improving a patient's physical or mental well-being.The treatment or amelioration of symptoms can be based on objective orsubjective parameters; including the results of a physical examination,neuropsychiatric exams, and/or a psychiatric evaluation. The term“treating” and conjugations thereof, include prevention of an injury,pathology, condition, or disease.

An “effective amount” is an amount sufficient to accomplish a statedpurpose (e.g. achieve the effect for which it is administered, treat adisease, reduce enzyme activity, increase enzyme activity, reduce one ormore symptoms of a disease or condition). An example of an “effectiveamount” is an amount sufficient to contribute to the treatment,prevention, or reduction of a symptom or symptoms of a disease, whichcould also be referred to as a “therapeutically effective amount.” A“reduction” of a symptom or symptoms (and grammatical equivalents ofthis phrase) means decreasing of the severity or frequency of thesymptom(s), or elimination of the symptom(s). A “prophylacticallyeffective amount” of a drug is an amount of a drug that, whenadministered to a subject, will have the intended prophylactic effect,e.g., preventing or delaying the onset (or reoccurrence) of an injury,disease, pathology or condition, or reducing the likelihood of the onset(or reoccurrence) of an injury, disease, pathology, or condition, ortheir symptoms. The full prophylactic effect does not necessarily occurby administration of one dose, and may occur only after administrationof a series of doses. Thus, a prophylactically effective amount may beadministered in one or more administrations. The exact amounts willdepend on the purpose of the treatment, and will be ascertainable by oneskilled in the art using known techniques (see, e.g., Lieberman,Pharmaceutical Dosage Forms (vols. 1-3, 1992); Lloyd, The Art, Scienceand Technology of Pharmaceutical Compounding (1999); Pickar, DosageCalculations (1999); and Remington: The Science and Practice ofPharmacy, 20th Edition, 2003, Gennaro, Ed., Lippincott, Williams &Wilkins).

For any compound described herein, the therapeutically effective amountcan be initially determined from cell culture assays. Targetconcentrations will be those concentrations of active compound(s) thatare capable of achieving the methods described herein, as measured usingthe methods described herein or known in the art.

As is well known in the art, therapeutically effective amounts for usein humans can also be determined from animal models. For example, a dosefor humans can be formulated to achieve a concentration that has beenfound to be effective in animals. The dosage in humans can be adjustedby monitoring compounds effectiveness and adjusting the dosage upwardsor downwards, as described above. Adjusting the dose to achieve maximalefficacy in humans based on the methods described above and othermethods is well within the capabilities of the ordinarily skilledartisan.

Dosages may be varied depending upon the requirements of the patient andthe compound being employed. The dose administered to a patient, in thecontext of the present invention should be sufficient to effect abeneficial therapeutic response in the patient over time. The size ofthe dose also will be determined by the existence, nature, and extent ofany adverse side-effects. Determination of the proper dosage for aparticular situation is within the skill of the practitioner. Generally,treatment is initiated with smaller dosages which are less than theoptimum dose of the compound. Thereafter, the dosage is increased bysmall increments until the optimum effect under circumstances isreached.

Dosage amounts and intervals can be adjusted individually to providelevels of the administered compound effective for the particularclinical indication being treated. This will provide a therapeuticregimen that is commensurate with the severity of the individual'sdisease state.

Utilizing the teachings provided herein, an effective prophylactic ortherapeutic treatment regimen can be planned that does not causesubstantial toxicity and yet is effective to treat the clinical symptomsdemonstrated by the particular patient. This planning should involve thecareful choice of active compound by considering factors such ascompound potency, relative bioavailability, patient body weight,presence and severity of adverse side effects, preferred mode ofadministration and the toxicity profile of the selected agent.

“Control” or “control experiment” is used in accordance with its plainordinary meaning and refers to an experiment in which the subjects orreagents of the experiment are treated as in a parallel experimentexcept for omission of a procedure, reagent, or variable of theexperiment. In some instances, the control is used as a standard ofcomparison in evaluating experimental effects. A control may be themeasurement of the activity of a protein in the absence of a compound asdescribed herein.

A “test compound” as used herein refers to an experimental compound usedin a screening process to identify activity, non-activity, or othermodulation of a particularized biological target or pathway.

The term “modulation”, “modulate”, or “modulator” are used in accordancewith their plain ordinary meaning and refer to the act of changing orvarying one or more properties. “Modulator” refers to a composition thatincreases or decreases the level of a target molecule or the function ofa target molecule or the physical state of the target of the molecule.“Modulation” refers to the process of changing or varying one or moreproperties. For example, as applied to the effects of a modulator on abiological target, to modulate means to change by increasing ordecreasing a property or function of the biological target or the amountof the biological target.

As defined herein, the term “inhibition”, “inhibit”, “inhibiting” andthe like in reference to a protein-inhibitor interaction meansnegatively affecting (e.g. decreasing) the activity or function of theprotein relative to the activity or function of the protein in theabsence of the inhibitor. Inhibition may refer to reduction of a diseaseor symptoms of disease. Inhibition may refer to a reduction in theactivity of a particular protein or nucleic acid target. Thus,inhibition includes, at least in part, partially or totally blockingstimulation, decreasing, preventing, or delaying activation, orinactivating, desensitizing, or down-regulating signal transduction orenzymatic activity or the amount of a protein.

“Contacting” is used in accordance with its plain ordinary meaning andrefers to the process of allowing at least two distinct species (e.g.chemical compounds including biomolecules or cells) to becomesufficiently proximal to react, interact or physically touch. It shouldbe appreciated; however, the resulting reaction product can be produceddirectly from a reaction between the added reagents or from anintermediate from one or more of the added reagents that can be producedin the reaction mixture.

The term “contacting” may include allowing two species to react,interact, or physically touch, wherein the two species may be a compoundas described herein and a protein or enzyme. Contacting may includeallowing a compound described herein to interact with a protein orenzyme that is involved in a signaling pathway.

“Patient,” “subject,” “patient in need thereof,” and “subject in needthereof” are herein used interchangeably and refer to a living organismsuffering from or prone to a disease or condition that can be treated byadministration of a pharmaceutical composition as provided herein.Non-limiting examples include humans, other mammals, bovines, rats,mice, dogs, monkeys, goat, sheep, cows, deer, and other non-mammaliananimals. A patient may be human.

“Disease” or “condition” or “disorder” refers to a state of being orhealth status of a patient or subject capable of being treated with thecompounds, drugs, pharmaceutical compositions, or methods providedherein. The disease may be a disease related to (e.g. caused by) anabnormal cell growth or abnormal protein activity (e.g. cancer).

As used herein, the term “cancer” refers to all types of cancer,neoplasm, or malignant or benign tumors found in mammals, includingleukemia, carcinomas and sarcomas. Exemplary cancers include acutemyeloid leukemia (“AML”), chronic myelogenous leukemia (“CML”), andcancer of the brain, breast, pancreas, colon, liver, kidney, lung,non-small cell lung, melanoma, ovary, sarcoma, and prostate. Additionalexamples include, cervix cancers, stomach cancers, head & neck cancers,uterus cancers, mesothelioma, metastatic bone cancer, Medulloblastoma,Hodgkin's Disease, Non-Hodgkin's Lymphoma, multiple myeloma,neuroblastoma, ovarian cancer, rhabdomyosarcoma, primary thrombocytosis,primary macroglobulinemia, primary brain tumors, cancer, malignantpancreatic insulanoma, malignant carcinoid, urinary bladder cancer,premalignant skin lesions, testicular cancer, lymphomas, thyroid cancer,neuroblastoma, esophageal cancer, genitourinary tract cancer, malignanthypercalcemia, endometrial cancer, adrenal cortical cancer, andneoplasms of the endocrine and exocrine pancreas.

The term “leukemia” refers broadly to progressive, malignant diseases ofthe blood-forming organs and is generally characterized by a distortedproliferation and development of leukocytes and their precursors in theblood and bone marrow. Leukemia is generally clinically classified onthe basis of (1) the duration and character of the disease-acute orchronic; (2) the type of cell involved; myeloid (myelogenous), lymphoid(lymphogenous), or monocytic; and (3) the increase or non-increase inthe number abnormal cells in the blood-leukemic or aleukemic(subleukemic). The murine leukemia model is widely accepted as beingpredictive of in vivo anti-leukemic activity. It is believed that acompound that tests positive in the P388 cell assay will generallyexhibit some level of anti-leukemic activity regardless of the type ofleukemia being treated. Accordingly, the present invention includes amethod of treating leukemia, including treating acute myeloid leukemia,chronic lymphocytic leukemia, acute granulocytic leukemia, chronicgranulocytic leukemia, acute promyelocytic leukemia, adult T-cellleukemia, aleukemic leukemia, a leukocythemic leukemia, basophylicleukemia, blast cell leukemia, bovine leukemia, chronic myelocyticleukemia, leukemia cutis, embryonal leukemia, eosinophilic leukemia,Gross' leukemia, hairy-cell leukemia, hemoblastic leukemia,hemocytoblastic leukemia, histiocytic leukemia, stem cell leukemia,acute monocytic leukemia, leukopenic leukemia, lymphatic leukemia,lymphoblastic leukemia, lymphocytic leukemia, lymphogenous leukemia,lymphoid leukemia, lymphosarcoma cell leukemia, mast cell leukemia,megakaryocytic leukemia, micromyeloblastic leukemia, monocytic leukemia,myeloblastic leukemia, myelocytic leukemia, myeloid granulocyticleukemia, myelomonocytic leukemia, Naegeli leukemia, plasma cellleukemia, multiple myeloma, plasmacytic leukemia, promyelocyticleukemia, Rieder cell leukemia, Schilling's leukemia, stem cellleukemia, subleukemic leukemia, and undifferentiated cell leukemia.

The term “sarcoma” generally refers to a tumor which is made up of asubstance like the embryonic connective tissue and is generally composedof closely packed cells embedded in a fibrillar or homogeneoussubstance. Sarcomas which can be treated with a combination ofantineoplastic thiol-binding mitochondrial oxidant and an anticanceragent include a chondrosarcoma, fibrosarcoma, lymphosarcoma,melanosarcoma, myxosarcoma, osteosarcoma, Abemethy's sarcoma, adiposesarcoma, liposarcoma, alveolar soft part sarcoma, ameloblastic sarcoma,botryoid sarcoma, chloroma sarcoma, chorio carcinoma, embryonal sarcoma,Wilms' tumor sarcoma, endometrial sarcoma, stromal sarcoma, Ewing'ssarcoma, fascial sarcoma, fibroblastic sarcoma, giant cell sarcoma,granulocytic sarcoma, Hodgkin's sarcoma, idiopathic multiple pigmentedhemorrhagic sarcoma, immunoblastic sarcoma of B cells, lymphoma,immunoblastic sarcoma of T-cells, Jensen's sarcoma, Kaposi's sarcoma,Kupffer cell sarcoma, angiosarcoma, leukosarcoma, malignant mesenchymomasarcoma, parosteal sarcoma, reticulocytic sarcoma, Rous sarcoma,serocystic sarcoma, synovial sarcoma, and telangiectaltic sarcoma.

The term “melanoma” is taken to mean a tumor arising from themelanocytic system of the skin and other organs. Melanomas which can betreated with a combination of antineoplastic thiol-binding mitochondrialoxidant and an anticancer agent include, for example, acral-lentiginousmelanoma, amelanotic melanoma, benign juvenile melanoma, Cloudman'smelanoma, S91 melanoma, Harding-Passey melanoma, juvenile melanoma,lentigo maligna melanoma, malignant melanoma, nodular melanoma, subungalmelanoma, and superficial spreading melanoma.

The term “carcinoma” refers to a malignant new growth made up ofepithelial cells tending to infiltrate the surrounding tissues and giverise to metastases. Exemplary carcinomas which can be treated with acombination of antineoplastic thiol-binding mitochondrial oxidant and ananticancer agent include, for example, acinar carcinoma, acinouscarcinoma, adenocystic carcinoma, adenoid cystic carcinoma, carcinomaadenomatosum, carcinoma of adrenal cortex, alveolar carcinoma, alveolarcell carcinoma, basal cell carcinoma, carcinoma basocellulare, basaloidcarcinoma, basosquamous cell carcinoma, bronchioalveolar carcinoma,bronchiolar carcinoma, bronchogenic carcinoma, cerebriform carcinoma,cholangiocellular carcinoma, chorionic carcinoma, colloid carcinoma,comedo carcinoma, corpus carcinoma, cribriform carcinoma, carcinoma encuirasse, carcinoma cutaneum, cylindrical carcinoma, cylindrical cellcarcinoma, duct carcinoma, carcinoma durum, embryonal carcinoma,encephaloid carcinoma, epiermoid carcinoma, carcinoma epithelialeadenoides, exophytic carcinoma, carcinoma ex ulcere, carcinoma fibrosum,gelatinifomi carcinoma, gelatinous carcinoma, giant cell carcinoma,carcinoma gigantocellulare, glandular carcinoma, granulosa cellcarcinoma, hair-matrix carcinoma, hematoid carcinoma, hepatocellularcarcinoma, Hurthle cell carcinoma, hyaline carcinoma, hypemephroidcarcinoma, infantile embryonal carcinoma, carcinoma in situ,intraepidermal carcinoma, intraepithelial carcinoma, Krompecher'scarcinoma, Kulchitzky-cell carcinoma, large-cell carcinoma, lenticularcarcinoma, carcinoma lenticulare, lipomatous carcinoma, lymphoepithelialcarcinoma, carcinoma medullare, medullary carcinoma, melanoticcarcinoma, carcinoma molle, mucinous carcinoma, carcinoma muciparum,carcinoma mucocellulare, mucoepidermoid carcinoma, carcinoma mucosum,mucous carcinoma, carcinoma myxomatodes, nasopharyngeal carcinoma, oatcell carcinoma, carcinoma ossificans, osteoid carcinoma, papillarycarcinoma, periportal carcinoma, preinvasive carcinoma, prickle cellcarcinoma, pultaceous carcinoma, renal cell carcinoma of kidney, reservecell carcinoma, carcinoma sarcomatodes, schneiderian carcinoma,scirrhous carcinoma, carcinoma scroti, signet-ring cell carcinoma,carcinoma simplex, small-cell carcinoma, solanoid carcinoma, spheroidalcell carcinoma, spindle cell carcinoma, carcinoma spongiosum, squamouscarcinoma, squamous cell carcinoma, string carcinoma, carcinomatelangiectaticum, carcinoma telangiectodes, transitional cell carcinoma,carcinoma tuberosum, tuberous carcinoma, verrucous carcinoma, andcarcinoma villosum.

“Anti-cancer agent” is used in accordance with its plain and ordinarymeaning and refers to a composition (e.g. compound, drug, antagonist,inhibitor, modulator) having antineoplastic properties or the ability toinhibit the growth or proliferation of cells. In some embodiments, ananti-cancer agent is a chemotherapeutic. An anti-cancer agent may be anagent approved by the FDA or similar regulatory agency of a countryother than the USA, for treating cancer.

Examples of anti-cancer agents include, but are not limited to, MEK(e.g. MEK1, MEK2, or MEK1 and MEK2) inhibitors (e.g. XL518, CI-1040,PD035901, selumetinib/AZD6244, GSK1120212/trametinib, GDC-0973,ARRY-162, ARRY-300, AZD8330, PD0325901, U0126, PD98059, TAK-733,PD318088, AS703026, BAY 869766), alkylating agents (e.g.,cyclophosphamide, ifosfamide, chlorambucil, busulfan, melphalan,mechlorethamine, uramustine, thiotepa, nitrosoureas, nitrogen mustards(e.g., mechloroethamine, cyclophosphamide, chlorambucil, meiphalan),ethylenimine and methylmelamines (e.g., hexamethlymelamine, thiotepa),alkyl sulfonates (e.g., busulfan), nitrosoureas (e.g., carmustine,lomusitne, semustine, streptozocin), triazenes (decarbazine)),anti-metabolites (e.g., 5-azathioprine, leucovorin, capecitabine,fludarabine, gemcitabine, pemetrexed, raltitrexed, folic acid analog(e.g., methotrexate), or pyrimidine analogs (e.g., fluorouracil,floxouridine, Cytarabine), purine analogs (e.g., mercaptopurine,thioguanine, pentostatin), etc.), plant alkaloids (e.g., vincristine,vinblastine, vinorelbine, vindesine, podophyllotoxin, paclitaxel,docetaxel, etc.), topoisomerase inhibitors (e.g., irinotecan, topotecan,amsacrine, etoposide (VP16), etoposide phosphate, teniposide, etc.),antitumor antibiotics (e.g., doxorubicin, adriamycin, daunorubicin,epirubicin, actinomycin, bleomycin, mitomycin, mitoxantrone, plicamycin,etc.), platinum-based compounds (e.g. cisplatin, oxaloplatin,carboplatin), anthracenedione (e.g., mitoxantrone), substituted urea(e.g., hydroxyurea), methyl hydrazine derivative (e.g., procarbazine),adrenocortical suppressant (e.g., mitotane, aminoglutethimide),epipodophyllotoxins (e.g., etoposide), antibiotics (e.g., daunorubicin,doxorubicin, bleomycin), enzymes (e.g., L-asparaginase), inhibitors ofmitogen-activated protein kinase signaling (e.g. U0126, PD98059,PD184352, PD0325901, ARRY-142886, SB239063, SP600125, BAY 43-9006,wortmannin, or LY294002, Syk inhibitors, mTOR inhibitors, antibodies(e.g., rituxan), gossyphol, genasense, polyphenol E, Chlorofusin, alltrans-retinoic acid (ATRA), bryostatin, tumor necrosis factor-relatedapoptosis-inducing ligand (TRAIL), 5-aza-2′-deoxycytidine, all transretinoic acid, doxorubicin, vincristine, etoposide, gemcitabine,imatinib (Gleevec®), geldanamycin,17-N-Allylamino-17-Demethoxygeldanamycin (17-AAG), flavopiridol,LY294002, bortezomib, trastuzumab, BAY 11-7082, PKC412, PD184352,20-epi-1, 25 dihydroxyvitamin D3; 5-ethynyluracil; abiraterone;aclarubicin; acylfulvene; adecypenol; adozelesin; aldesleukin; ALL-TKantagonists; altretamine; ambamustine; amidox; amifostine;aminolevulinic acid; amrubicin; amsacrine; anagrelide; anastrozole;andrographolide; angiogenesis inhibitors; antagonist D; antagonist G;antarelix; anti-dorsalizing morphogenetic protein-1; antiandrogen,prostatic carcinoma; antiestrogen; antineoplaston; antisenseoligonucleotides; aphidicolin glycinate; apoptosis gene modulators;apoptosis regulators; apurinic acid; ara-CDP-DL-PTBA; argininedeaminase; asulacrine; atamestane; atrimustine; axinastatin 1;axinastatin 2; axinastatin 3; azasetron; azatoxin; azatyrosine; baccatinIII derivatives; balanol; batimastat; BCR/ABL antagonists;benzochlorins; benzoylstaurosporine; beta lactam derivatives;beta-alethine; betaclamycin B; betulinic acid; bFGF inhibitor;bicalutamide; bisantrene; bisaziridinylspermine; bisnafide; bistrateneA; bizelesin; breflate; bropirimine; budotitane; buthionine sulfoximine;calcipotriol; calphostin C; camptothecin derivatives; canarypox IL-2;capecitabine; carboxamide-amino-triazole; carboxyamidotriazole; CaRestM3; CARN 700; cartilage derived inhibitor; carzelesin; casein kinaseinhibitors (ICOS); castanospermine; cecropin B; cetrorelix; chlorins;chloroquinoxaline sulfonamide; cicaprost; cis-porphyrin; cladribine;clomifene analogues; clotrimazole; collismycin A; collismycin B;combretastatin A4; combretastatin analogue; conagenin; crambescidin 816;crisnatol; cryptophycin 8; cryptophycin A derivatives; curacin A;cyclopentanthraquinones; cycloplatam; cypemycin; cytarabine ocfosfate;cytolytic factor; cytostatin; dacliximab; decitabine; dehydrodidemnin B;deslorelin; dexamethasone; dexifosfamide; dexrazoxane; dexverapamil;diaziquone; didemnin B; didox; diethylnorspermine;dihydro-5-azacytidine; 9-dioxamycin; diphenyl spiromustine; docosanol;dolasetron; doxifluridine; droloxifene; dronabinol; duocarmycin SA;ebselen; ecomustine; edelfosine; edrecolomab; eflomithine; elemene;emitefur; epirubicin; epristeride; estramustine analogue; estrogenagonists; estrogen antagonists; etanidazole; etoposide phosphate;exemestane; fadrozole; fazarabine; fenretinide; filgrastim; finasteride;flavopiridol; flezelastine; fluasterone; fludarabine; fluorodaunorunicinhydrochloride; forfenimex; formestane; fostriecin; fotemustine;gadolinium texaphyrin; gallium nitrate; galocitabine; ganirelix;gelatinase inhibitors; gemcitabine; glutathione inhibitors; hepsulfam;heregulin; hexamethylene bisacetamide; hypericin; ibandronic acid;idarubicin; idoxifene; idramantone; ilmofosine; ilomastat;imidazoacridones; imiquimod; immunostimulant peptides; insulin-likegrowth factor-1 receptor inhibitor; interferon agonists; interferons;interleukins; iobenguane; iododoxorubicin; ipomeanol, 4-; iroplact;irsogladine; isobengazole; isohomohalicondrin B; itasetron;jasplakinolide; kahalalide F; lamellarin-N triacetate; lanreotide;leinamycin; lenograstim; lentinan sulfate; leptolstatin; letrozole;leukemia inhibiting factor; leukocyte alpha interferon;leuprolide+estrogen+progesterone; leuprorelin; levamisole; liarozole;linear polyamine analogue; lipophilic disaccharide peptide; lipophilicplatinum compounds; lissoclinamide 7; lobaplatin; lombricine;lometrexol; lonidamine; losoxantrone; lovastatin; loxoribine;lurtotecan; lutetium texaphyrin; lysofylline; lytic peptides;maitansine; mannostatin A; marimastat; masoprocol; maspin; matrilysininhibitors; matrix metalloproteinase inhibitors; menogaril; merbarone;meterelin; methioninase; metoclopramide; MIF inhibitor; mifepristone;miltefosine; mirimostim; mismatched double stranded RNA; mitoguazone;mitolactol; mitomycin analogues; mitonafide; mitotoxin fibroblast growthfactor-saporin; mitoxantrone; mofarotene; molgramostim; monoclonalantibody, human chorionic gonadotrophin; monophosphoryl lipidA+myobacterium cell wall sk; mopidamol; multiple drug resistance geneinhibitor; multiple tumor suppressor 1-based therapy; mustard anticanceragent; mycaperoxide B; mycobacterial cell wall extract; myriaporone;N-acetyldinaline; N-substituted benzamides; nafarelin; nagrestip;naloxone+pentazocine; napavin; naphterpin; nartograstim; nedaplatin;nemorubicin; neridronic acid; neutral endopeptidase; nilutamide;nisamycin; nitric oxide modulators; nitroxide antioxidant; nitrullyn;O6-benzylguanine; octreotide; okicenone; oligonucleotides; onapristone;ondansetron; ondansetron; oracin; oral cytokine inducer; ormaplatin;osaterone; oxaliplatin; oxaunomycin; palauamine; palmitoylrhizoxin;pamidronic acid; panaxytriol; panomifene; parabactin; pazelliptine;pegaspargase; peldesine; pentosan polysulfate sodium; pentostatin;pentrozole; perflubron; perfosfamide; perillyl alcohol; phenazinomycin;phenylacetate; phosphatase inhibitors; picibanil; pilocarpinehydrochloride; pirarubicin; piritrexim; placetin A; placetin B;plasminogen activator inhibitor; platinum complex; platinum compounds;platinum-triamine complex; porfimer sodium; porfiromycin; prednisone;propyl bis-acridone; prostaglandin J2; proteasome inhibitors; proteinA-based immune modulator; protein kinase C inhibitor; protein kinase Cinhibitors, microalgal; protein tyrosine phosphatase inhibitors; purinenucleoside phosphorylase inhibitors; purpurins; pyrazoloacridine;pyridoxylated hemoglobin polyoxyethylerie conjugate; raf antagonists;raltitrexed; ramosetron; ras farnesyl protein transferase inhibitors;ras inhibitors; ras-GAP inhibitor; retelliptine demethylated; rhenium Re186 etidronate; rhizoxin; ribozymes; RII retinamide; rogletimide;rohitukine; romurtide; roquinimex; rubiginone B1; ruboxyl; safingol;saintopin; SarCNU; sarcophytol A; sargramostim; Sdi 1 mimetics;semustine; senescence derived inhibitor 1; sense oligonucleotides;signal transduction inhibitors; signal transduction modulators; singlechain antigen-binding protein; sizofuran; sobuzoxane; sodiumborocaptate; sodium phenylacetate; solverol; somatomedin bindingprotein; sonermin; sparfosic acid; spicamycin D; spiromustine;splenopentin; spongistatin 1; squalamine; stem cell inhibitor; stem-celldivision inhibitors; stipiamide; stromelysin inhibitors; sulfinosine;superactive vasoactive intestinal peptide antagonist; suradista;suramin; swainsonine; synthetic glycosaminoglycans; tallimustine;tamoxifen methiodide; tauromustine; tazarotene; tecogalan sodium;tegafur; tellurapyrylium; telomerase inhibitors; temoporfin;temozolomide; teniposide; tetrachlorodecaoxide; tetrazomine;thaliblastine; thiocoraline; thrombopoietin; thrombopoietin mimetic;thymalfasin; thymopoietin receptor agonist; thymotrinan; thyroidstimulating hormone; tin ethyl etiopurpurin; tirapazamine; titanocenebichloride; topsentin; toremifene; totipotent stem cell factor;translation inhibitors; tretinoin; triacetyluridine; triciribine;trimetrexate; triptorelin; tropisetron; turosteride; tyrosine kinaseinhibitors; tyrphostins; UBC inhibitors; ubenimex; urogenitalsinus-derived growth inhibitory factor; urokinase receptor antagonists;vapreotide; variolin B; vector system, erythrocyte gene therapy;velaresol; veramine; verdins; verteporfin; vinorelbine; vinxaltine;vitaxin; vorozole; zanoterone; zeniplatin; zilascorb; zinostatinstimalamer, Adriamycin, Dactinomycin, Bleomycin, Vinblastine, Cisplatin,acivicin; aclarubicin; acodazole hydrochloride; acronine; adozelesin;aldesleukin; altretamine; ambomycin; ametantrone acetate;aminoglutethimide; amsacrine; anastrozole; anthramycin; asparaginase;asperlin; azacitidine; azetepa; azotomycin; batimastat; benzodepa;bicalutamide; bisantrene hydrochloride; bisnafide dimesylate; bizelesin;bleomycin sulfate; brequinar sodium; bropirimine; busulfan;cactinomycin; calusterone; caracemide; carbetimer; carboplatin;carmustine; carubicin hydrochloride; carzelesin; cedefingol;chlorambucil; cirolemycin; cladribine; crisnatol mesylate;cyclophosphamide; cytarabine; dacarbazine; daunorubicin hydrochloride;decitabine; dexormaplatin; dezaguanine; dezaguanine mesylate;diaziquone; doxorubicin; doxorubicin hydrochloride; droloxifene;droloxifene citrate; dromostanolone propionate; duazomycin; edatrexate;eflomithine hydrochloride; elsamitrucin; enloplatin; enpromate;epipropidine; epirubicin hydrochloride; erbulozole; esorubicinhydrochloride; estramustine; estramustine phosphate sodium; etanidazole;etoposide; etoposide phosphate; etoprine; fadrozole hydrochloride;fazarabine; fenretinide; floxuridine; fludarabine phosphate;fluorouracil; fluorocitabine; fosquidone; fostriecin sodium;gemcitabine; gemcitabine hydrochloride; hydroxyurea; idarubicinhydrochloride; ifosfamide; iimofosine; interleukin I1 (includingrecombinant interleukin II, or rlL.sub.2), interferon alfa-2a;interferon alfa-2b; interferon alfa-n1; interferon alfa-n3; interferonbeta-1a; interferon gamma-1b; iproplatin; irinotecan hydrochloride;lanreotide acetate; letrozole; leuprolide acetate; liarozolehydrochloride; lometrexol sodium; lomustine; losoxantrone hydrochloride;masoprocol; maytansine; mechlorethamine hydrochloride; megestrolacetate; melengestrol acetate; melphalan; menogaril; mercaptopurine;methotrexate; methotrexate sodium; metoprine; meturedepa; mitindomide;mitocarcin; mitocromin; mitogillin; mitomalcin; mitomycin; mitosper;mitotane; mitoxantrone hydrochloride; mycophenolic acid; nocodazoie;nogalamycin; ormaplatin; oxisuran; pegaspargase; peliomycin;pentamustine; peplomycin sulfate; perfosfamide; pipobroman; piposulfan;piroxantrone hydrochloride; plicamycin; plomestane; porfimer sodium;porfiromycin; prednimustine; procarbazine hydrochloride; puromycin;puromycin hydrochloride; pyrazofurin; riboprine; rogletimide; safingol;safingol hydrochloride; semustine; simtrazene; sparfosate sodium;sparsomycin; spirogermanium hydrochloride; spiromustine; spiroplatin;streptonigrin; streptozocin; sulofenur; talisomycin; tecogalan sodium;tegafur; teloxantrone hydrochloride; temoporfin; teniposide; teroxirone;testolactone; thiamiprine; thioguanine; thiotepa; tiazofurin;tirapazamine; toremifene citrate; trestolone acetate; triciribinephosphate; trimetrexate; trimetrexate glucuronate; triptorelin;tubulozole hydrochloride; uracil mustard; uredepa; vapreotide;verteporfin; vinblastine sulfate; vincristine sulfate; vindesine;vindesine sulfate; vinepidine sulfate; vinglycinate sulfate;vinleurosine sulfate; vinorelbine tartrate; vinrosidine sulfate;vinzolidine sulfate; vorozole; zeniplatin; zinostatin; zorubicinhydrochloride, agents that arrest cells in the G2-M phases and/ormodulate the formation or stability of microtubules, (e.g. Taxol™ (i.e.paclitaxel), Taxotere™, compounds comprising the taxane skeleton,Erbulozole (i.e. R-55104), Dolastatin 10 (i.e. DLS-10 and NSC-376128),Mivobulin isethionate (i.e. as CI-980), Vincristine, NSC-639829,Discodermolide (i.e. as NVP-XX-A-296), ABT-751 (Abbott, i.e. E-7010),Altorhyrtins (e.g. Altorhyrtin A and Altorhyrtin C), Spongistatins (e.g.Spongistatin 1, Spongistatin 2, Spongistatin 3, Spongistatin 4,Spongistatin 5, Spongistatin 6, Spongistatin 7, Spongistatin 8, andSpongistatin 9), Cemadotin hydrochloride (i.e. LU-103793 andNSC-D-669356), Epothilones (e.g. Epothilone A, Epothilone B, EpothiloneC (i.e. desoxyepothilone A or dEpoA), Epothilone D (i.e. KOS-862, dEpoB,and desoxyepothilone B), Epothilone E, Epothilone F, Epothilone BN-oxide, Epothilone A N-oxide, 16-aza-epothilone B, 21-aminoepothilone B(i.e. BMS-310705), 21-hydroxyepothilone D (i.e. Desoxyepothilone F anddEpoF), 26-fluoroepothilone, Auristatin PE (i.e. NSC-654663), Soblidotin(i.e. TZT-1027), LS-4559-P (Pharmacia, i.e. LS-4577), LS-4578(Pharmacia, i.e. LS-477-P), LS-4477 (Pharmacia), LS-4559 (Pharmacia),RPR-112378 (Aventis), Vincristine sulfate, DZ-3358 (Daiichi), FR-182877(Fujisawa, i.e. WS-9885B), GS-164 (Takeda), GS-198 (Takeda), KAR-2(Hungarian Academy of Sciences), BSF-223651 (BASF, i.e. ILX-651 andLU-223651), SAH-49960 (Lilly/Novartis), SDZ-268970 (Lilly/Novartis),AM-97 (Armad/Kyowa Hakko), AM-132 (Armad), AM-138 (Armad/Kyowa Hakko),IDN-5005 (Indena), Cryptophycin 52 (i.e. LY-355703), AC-7739 (Ajinomoto,i.e. AVE-8063A and CS-39.HCl), AC-7700 (Ajinomoto, i.e. AVE-8062,AVE-8062A, CS-39-L-Ser.HCl, and RPR-258062A), Vitilevuamide, TubulysinA, Canadensol, Centaureidin (i.e. NSC-106969), T-138067 (Tularik, i.e.T-67, TL-138067 and TI-138067), COBRA-1 (Parker Hughes Institute, i.e.DDE-261 and WHI-261), H10 (Kansas State University), H16 (Kansas StateUniversity), Oncocidin A1 (i.e. BTO-956 and DIME), DDE-313 (ParkerHughes Institute), Fijianolide B, Laulimalide, SPA-2 (Parker HughesInstitute), SPA-1 (Parker Hughes Institute, i.e. SPIKET-P), 3-IAABU(Cytoskeleton/Mt. Sinai School of Medicine, i.e. MF-569), Narcosine(also known as NSC-5366), Nascapine, D-24851 (Asta Medica), A-105972(Abbott), Hemiasterlin, 3-BAABU (Cytoskeleton/Mt. Sinai School ofMedicine, i.e. MF-191), TMPN (Arizona State University), Vanadoceneacetylacetonate, T-138026 (Tularik), Monsatrol, Inanocine (i.e.NSC-698666), 3-IAABE (Cytoskeleton/Mt. Sinai School of Medicine),A-204197 (Abbott), T-607 (Tuiarik, i.e. T-900607), RPR-115781 (Aventis),Eleutherobins (such as Desmethyleleutherobin, Desaetyleleutherobin,Isoeleutherobin A, and Z-Eleutherobin), Caribaeoside, Caribaeolin,Halichondrin B, D-64131 (Asta Medica), D-68144 (Asta Medica),Diazonamide A, A-293620 (Abbott), NPI-2350 (Nereus), Taccalonolide A,TUB-245 (Aventis), A-259754 (Abbott), Diozostatin, (−)-Phenylahistin(i.e. NSCL-96F037), D-68838 (Asta Medica), D-68836 (Asta Medica),Myoseverin B, D-43411 (Zentaris, i.e. D-81862), A-289099 (Abbott),A-318315 (Abbott), HTI-286 (i.e. SPA-10, trifluoroacetate salt) (Wyeth),D-82317 (Zentaris), D-82318 (Zentaris), SC-12983 (NCI), Resverastatinphosphate sodium, BPR-OY-007 (National Health Research Institutes), andSSR-250411 (Sanofi)), steroids (e.g., dexamethasone), finasteride,aromatase inhibitors, gonadotropin-releasing hormone agonists (GnRH)such as goserelin or leuprolide, adrenocorticosteroids (e.g.,prednisone), progestins (e.g., hydroxyprogesterone caproate, megestrolacetate, medroxyprogesterone acetate), estrogens (e.g.,diethlystilbestrol, ethinyl estradiol), antiestrogen (e.g., tamoxifen),androgens (e.g., testosterone propionate, fluoxymesterone), antiandrogen(e.g., flutamide), immunostimulants (e.g., Bacillus Calmette-Gudrin(BCG), levamisole, interleukin-2, alpha-interferon, etc.), monoclonalantibodies (e.g., anti-CD20, anti-HER2, anti-CD52, anti-HLA-DR, andanti-VEGF monoclonal antibodies), immunotoxins (e.g., anti-CD33monoclonal antibody-calicheamicin conjugate, anti-CD22 monoclonalantibody-pseudomonas exotoxin conjugate, etc.), radioimmunotherapy(e.g., anti-CD20 monoclonal antibody conjugated to ¹¹¹In, ⁹⁰Y, or ¹³¹I,etc.), triptolide, homoharringtonine, dactinomycin, doxorubicin,epirubicin, topotecan, itraconazole, vindesine, cerivastatin,vincristine, deoxyadenosine, sertraline, pitavastatin, irinotecan,clofazimine, 5-nonyloxytryptamine, vemurafenib, dabrafenib, erlotinib,gefitinib, EGFR inhibitors, epidermal growth factor receptor(EGFR)-targeted therapy or therapeutic (e.g. gefitinib (Iressa™),erlotinib (Tarceva™), cetuximab (Erbitux), lapatinib (Tykerb™),panitumumab (Vectibix™), vandetanib (Caprelsa™), afatinib/BIBW2992,CI-1033/canertinib, neratinib/HKI-272, CP-724714, TAK-285, AST-1306,ARRY334543, ARRY-380, AG-1478, dacomitinib/PF299804, OSI-420/desmethylerlotinib, AZD8931, AEE788, pelitinib/EKB-569, CUDC-101, WZ8040, WZ4002,WZ3146, AG-490, XL647, PD153035, BMS-599626), sorafenib, imatinib,sunitinib, dasatinib, or the like.

“Chemotherapeutic” or “chemotherapeutic agent” is used in accordancewith its plain ordinary meaning and refers to a chemical composition orcompound having antineoplastic properties or the ability to inhibit thegrowth or proliferation of cells.

“Cancer model organism”, as used herein, is an organism exhibiting aphenotype indicative of cancer, or the activity of cancer causingelements, within the organism. The term cancer is defined above. A widevariety of organisms may serve as cancer model organisms, and includefor example, cancer cells and mammalian organisms such as rodents (e.g.mouse or rat) and primates (such as humans). Cancer cell lines arewidely understood by those skilled in the art as cells exhibitingphenotypes or genotypes similar to in vivo cancers. Cancer cell lines asused herein includes cell lines from animals (e.g. mice) and fromhumans.

I. COMPOSITIONS

Provided herein are compounds for treating cancer. The compound hasformula (I):

In the compound of formula (I), A is cycloalkyl, heterocycloalkyl, aryl,or heteroaryl. X is —C(R⁴)═ or —N═. Y is a bond, —N(R⁵)—, —O—, or —S—.L¹ is a bond, —C(O)—, —C(O)O—, —O—, —S—, —N(R⁶)—, —C(O)N(R⁶)—,—S(O)_(n6)—, —S(O)N(R⁶)—, substituted or unsubstituted alkylene,substituted or unsubstituted heteroalkylene, substituted orunsubstituted cycloalkylene, substituted or unsubstitutedheterocycloalkylene, substituted or unsubstituted arylene, orsubstituted or unsubstituted heteroarylene. R¹ is halogen, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —OR^(1A), —C(O)R^(1A), —NR^(1A)R^(1B),—C(O)OR^(1A), —C(O)NR^(1A)R^(1B), —NO₂, —SR^(1A), —S(O)_(n1)R^(1A),—S(O)_(n1)OR^(1A), —S(O)_(n1)NR^(1A)R^(1B), —NHNR^(1A)R^(1B),—ONR^(1A)R^(1B), —NHC(O)NHNR^(1A)R^(1B), substituted or unsubstitutedalkyl, substituted or unsubstituted heteroalkyl, substituted orunsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl,substituted or unsubstituted aryl, or substituted or unsubstitutedheteroaryl. R² is halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(2A),—C(O)R^(2A), —NR^(2A)R^(2B), —C(O)OR^(2A), —C(O)NR^(2A)R^(2B), —NO₂,—SR^(2A), —S(O)_(n2)R^(2A), —S(O)_(n2)OR^(2A), —S(O)_(n2)NR^(2A)R^(2B),—NHNR^(2A)R^(2B), —ONR^(2A)R^(2B), —NHC(O)NHNR^(2A)R^(2B), substitutedor unsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R³ is independently hydrogen, halogen, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, substituted orunsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R⁴ is hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(4A), —C(O)R^(4A), —NR^(4A)R^(4B), —C(O)OR^(4A),—C(O)NR^(4A)R^(4B), —NO₂, —SR^(4A), —S(O)_(n4)R^(4A), —S(O)_(n4)OR^(4A),—S(O)_(n4)NR^(4A)R^(4B), —NHNR^(4A)R^(4B), —ONR^(4A)R^(4B),—NHC(O)NHNR^(4A)R^(4B), substituted or unsubstituted C₁-C₅ alkyl, orsubstituted or unsubstituted 2 to 5 membered heteroalkyl. R⁵ ishydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(5A),—C(O)R^(5A), —NR^(5A)R^(5B), —C(O)OR^(5A), —C(O)NR^(5A)R^(5B), —NO₂,—SR^(5A), —S(O)_(n5)R^(5A), —S(O)_(n5)OR^(5A), —S(O)_(n5)NR^(5A)R^(5B),—NHNR^(5A)R^(5B), —ONR^(5A)R^(5B), —NHC(O)NHNR^(5A)R^(5B), substitutedor unsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R⁶ is hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(6A), —C(O)R^(6A), —NR^(6A)R^(6B), —C(O)OR^(6A),—C(O)NR^(6A)R^(6B), —NO₂, —SR^(6A), —S(O)R^(6A), —S(O)_(n6)OR^(6A),—S(O)_(n6)NR^(6A)R^(6B), —NHNR^(6A)R^(6B), —ONR^(6A)R^(6B),—NHC(O)NHNR^(6A)R^(6B), substituted or unsubstituted alkyl, substitutedor unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl. R^(1A),R^(1B), R^(2A), R^(2B), R^(4A), R^(4B), R^(5A), R^(5B), R^(6A), andR^(6B) are independently hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂,—COOH, —CONH₂, —NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂,—ONH₂, —NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH,—OCF₃, —OCHF₂, substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl. Thesymbols n1, n2, n4, n5, and n6 are independently 1, 2, or 3. The symbolm1 is 0, 1, 2, 3, or 4. The symbol m2 is 0, 1, 2, 3, 4, 5, or 6. Thesymbol m3 is 0, 1, or 2.

Ring A may be heterocycloalkyl, aryl, or heteroaryl. Ring A may beheterocycloalkyl or aryl. Ring A may be aryl or heteroaryl. Ring A maybe heterocycloalkyl or heteroaryl.

Ring A may be cycloalkyl. Ring A may be a 3 to 10 membered cycloalkyl.Ring A may be 3 to 8 membered cycloalkyl. Ring A may be 3 to 6 memberedcycloalkyl. Ring A may be cyclopropanyl. Ring A may be cyclopropenyl.Ring A may be cyclobutanyl. Ring A may be cyclobutenyl. Ring A may becyclopentanyl. Ring A may be cyclopentenyl. Ring A may be cyclohexanyl.Ring A may be cyclohexenyl. Ring A may be cyclopentanyl, cyclopentenyl,cyclohexanyl, or cyclohexenyl.

Ring A may be heterocycloalkyl or heteroaryl. Ring A may beheterocycloalkyl. Ring A may be 3 to 10 membered heterocycloalkyl. RingA may be 3 to 8 membered heterocycloalkyl. Ring A may be 3 to 6 memberedheterocycloalkyl. Ring A may be 3 membered heterocycloalkyl. Ring A maybe 4 membered heterocycloalkyl. Ring A may be aziridinyl, azirinyl,oxiranyl, oxirenyl, thiiranyl, thiirenyl, azetidinyl, azetyl, oxetanyl,oxetyl, thietanyl, or thietyl.

Ring A may be 5 membered heterocycloalkyl. Ring A may be 6 memberedheterocycloalkyl. Ring A may be tetrahydrofuranyl, tetrahydropyranyl,tetrahydrothiopyranyl, pyranyl, thianyl, dioxanyl, piperidinyl,piperazinyl, oxathianyl, morpholinyl, trioxanyl, pyrrolinyl,pyrrolidinyl, pyrrolidonyl, pyrrolidionyl, pyrazolidinyl, imidazolinyl,imidazolidinyl, isoxazolinyl, isoxazolidinyl, oxazolinyl, oxazolidinyl,oxazolidinonyl, or thiazolidinyl

Ring A may be aryl. Ring A may be 5 to 10 membered aryl. Ring A may be 5or 6 membered aryl. Ring A may be 5 membered aryl. Ring A may be 6membered aryl. Ring A may be phenylene. Ring A may be heteroaryl. Ring Amay be 5 to 10 membered heteroaryl. Ring A may be 5 or 6 memberedheteroaryl. Ring A may be 5 membered heteroaryl. Ring A may be 6membered heteroaryl. Ring A may be pyrroyl, furanyl, thiophenyl,imidazolyl, oxazolyl, isoxazolyl, thiazolyl, pyrazoyl, furyl, thienyl,triazolyl, tetrazolyl, pyridinyl, pyrimidinyl, pyrazinyl, orpyridazinyl.

Ring A may be a 5,6-, 6,5-, or 6,6-fused ring aryl or 5,6-, 6,5-, or6,6-fused ring heteroaryl as described herein. Ring A may be a 5,6-fusedring aryl. Ring A may be a 5,6-fused ring heteroaryl. Ring A may be a6,5-fused ring aryl. Ring A may be a 6,5-fused ring heteroaryl. Ring Amay be 6,6-fused ring aryl. Ring A may be a 6,6-fused ring heteroaryl.Ring A may indenyl, indolyl, isoindolyl, indolizinyl, purinyl,benzothiazolyl, benzoxazoyl, benzoimidazoyl, benzofuranyl,isobenzofuranyl indazolyl, pyrrollopyridinyl, pyrrollopyrimidinyl,pyrazolopyridinyl, imidazopyridinyl, benzotriazolyl, benzothiophenyl,quinolyl, quinolinyl, isoquinolyl, naphthalenyl, cinnolinyl,phthalazinyl, isoquinolinyl, quinoxalinyl, or quinazolinyl.

The symbol m2 may be 0. The symbol m2 may be 1. The symbol m2 may be 1,2, 3, 4, 5, or 6. The symbol m2 may be 1, 2, or 3. The symbols n1, n2,n4, n5, and n6 may independently be 1. The symbols n1, n2, n4, n5, andn6 may independently be 2. The symbols n1, n2, n4, n5, and n6 mayindependently be 3.

R¹ may be halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(1A),—C(O)R^(1A), —NR^(1A)R^(1B), —C(O)OR^(1A), —C(O)NR^(1A)R^(1B), —NO₂,—SR^(1A), —S(O)_(n1)R^(1A), —S(O)_(n1)OR^(1A), —S(O)_(n1)NR^(1A)R^(1B),—NHNR^(1A)R^(1B), —ONR^(1A)R^(1B), —NHC(O)NHNR^(1A)R^(1B). R¹ may behalogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(1A), —C(O)R^(1A),—NR^(1A)R^(1B), —C(O)OR^(1A), —C(O)NR^(1A)R^(1B), —NO₂, —SR^(1A). R¹ maybe halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(1A), —NH₂, —C(O)OH,—C(O)NH₂, —NO₂, or —SH. R¹ may be halogen, —CF₃, —NO₂, —NH₂, —OR^(1A).R¹ may be halogen. R¹ may be F. R¹ may be Cl. R¹ may be Br. R¹ may be I.R¹ may be —CF₃. R¹ may be —NH₂. R¹ may be —OR^(1A), where R^(1A) is asdefined herein. R¹ may be —OR^(1A) where R^(1A) is substituted orunsubstituted alkyl, substituted or unsubstituted heteroalkyl, orsubstituted or unsubstituted aryl. R¹ may be —OR^(1A) where R^(1A) issubstituted or unsubstituted alkyl. R¹ may be —OR^(1A) where R^(1A) isunsubstituted alkyl. R¹ may be —OR^(1A) where R^(1A) is unsubstitutedC₁-C₅ alkyl. R¹ may be —OR^(1A) where R^(1A) is unsubstituted C₁-C₃alkyl. R¹ may be —OR^(1A) where R^(1A) is methyl (e.g. —OCH₃). R¹ may behalogen, —CF₃, —NO₂, —NH₂, —OR^(1A), substituted or unsubstituted alkyl,substituted or unsubstituted heteroalkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heterocycloalkyl, substitutedor unsubstituted aryl, or substituted or unsubstituted heteroaryl.

R¹ may be substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl.

R¹ may be substituted or unsubstituted alkyl. R¹ may be substitutedalkyl. R¹ may be unsubstituted alkyl. R¹ may be substituted orunsubstituted C₁-C₂₀ alkyl. R¹ may be substituted C₁-C₂₀ alkyl. R¹ maybe unsubstituted C₁-C₂₀ alkyl. R¹ may be substituted or unsubstitutedC₁-C₁₀ alkyl. R¹ may be substituted C₁-C₁₀ alkyl. R¹ may beunsubstituted C₁-C₁₀ alkyl. R¹ may be substituted or unsubstituted C₁-C₅alkyl. R¹ may be substituted C₁-C₅ alkyl. R¹ may be unsubstituted C₁-C₅alkyl. R¹ may be substituted or unsubstituted C₁-C₃ alkyl. R¹ may besubstituted C₁-C₃ alkyl. R¹ may be unsubstituted C₁-C₃ alkyl. R¹ may bemethyl. R¹ may be ethyl. R¹ may be propyl.

R¹ may be R¹⁰-substituted or unsubstituted alkyl. R¹ may beR¹⁰-substituted alkyl. R¹ may be R¹⁰-substituted or unsubstituted C₁-C₂₀alkyl. R¹ may be substituted C₁-C₂₀ alkyl. R¹ may be R¹⁰-substituted orunsubstituted C₁-C₁₀ alkyl. R¹ may be R¹⁰-substituted C₁-C₁₀ alkyl. R¹may be R¹⁰-substituted or unsubstituted C₁-C₅ alkyl. R¹ may beR¹⁰-substituted C₁-C₅ alkyl. R¹ may be R¹⁰-substituted or unsubstitutedC₁-C₃ alkyl. R¹ may be R¹⁰-substituted C₁-C₃ alkyl.

R¹ may be substituted or unsubstituted 2 to 20 membered heteroalkyl. R¹may be substituted 2 to 20 membered heteroalkyl. R¹ may be unsubstituted2 to 20 membered heteroalkyl. R¹ may be substituted or unsubstituted 2to 10 membered heteroalkyl. R¹ may be substituted 2 to 10 memberedheteroalkyl. R¹ may be unsubstituted 2 to 10 membered heteroalkyl. R¹may be substituted or unsubstituted 2 to 6 membered heteroalkyl. R¹ maybe substituted 2 to 6 membered heteroalkyl. R¹ may be unsubstituted 2 to6 membered heteroalkyl. R¹ may be substituted or unsubstituted 2 to 5membered heteroalkyl. R¹ may be substituted 2 to 5 membered heteroalkyl.R¹ may be unsubstituted 2 to 5 membered heteroalkyl.

R¹ may be R¹⁰-substituted or unsubstituted 2 to 20 membered heteroalkyl.R¹ may be R¹⁰-substituted 2 to 20 membered heteroalkyl. R¹ may beR¹⁰-substituted or unsubstituted 2 to 10 membered heteroalkyl. R¹ may beR¹⁰-substituted 2 to 10 membered heteroalkyl. R¹ may be R¹⁰-substitutedor unsubstituted 2 to 6 membered heteroalkyl. R¹ may be R¹⁰-substituted2 to 6 membered heteroalkyl. R¹ may be R¹⁰-substituted or unsubstituted2 to 5 membered heteroalkyl. R¹ may be R¹⁰-substituted 2 to 5 memberedheteroalkyl.

R¹ may be substituted or unsubstituted 3 to 10 membered cycloalkyl. R¹may be substituted 3 to 10 membered cycloalkyl. R¹ may be unsubstituted3 to 10 membered cycloalkyl. R¹ may be substituted or unsubstituted 3 to6 membered cycloalkyl. R¹ may be substituted 3 to 6 membered cycloalkyl.R¹ may be unsubstituted 3 to 6 membered cycloalkyl. R¹ may besubstituted or unsubstituted 3 to 5 membered cycloalkyl. R¹ may besubstituted 3 to 5 membered cycloalkyl. R¹ may be unsubstituted 3 to 5membered cycloalkyl. R¹ may be substituted or unsubstituted 3 memberedcycloalkyl. R¹ may be substituted 3 membered cycloalkyl. R¹ may beunsubstituted 3 membered cycloalkyl. R¹ may be substituted orunsubstituted 4 membered cycloalkyl. R¹ may be substituted 4 memberedcycloalkyl. R¹ may be unsubstituted 4 membered cycloalkyl. R¹ may besubstituted or unsubstituted 5 membered cycloalkyl. R¹ may besubstituted 5 membered cycloalkyl. R¹ may be unsubstituted 5 memberedcycloalkyl. R¹ may be substituted or unsubstituted 6 memberedcycloalkyl. R¹ may be substituted 6 membered cycloalkyl. R¹ may beunsubstituted 6 membered cycloalkyl.

R¹ may be R¹⁰-substituted or unsubstituted 3 to 10 membered cycloalkyl.R¹ may be R¹⁰-substituted 3 to 10 membered cycloalkyl. R¹ may beR¹⁰-substituted or unsubstituted 3 to 6 membered cycloalkyl. R¹ may beR¹⁰-substituted 3 to 6 membered cycloalkyl. R¹ may be R¹⁰-substituted orunsubstituted 3 to 5 membered cycloalkyl. R¹ may be R¹⁰-substituted 3 to5 membered cycloalkyl. R¹ may be R¹⁰-substituted or unsubstituted 3membered cycloalkyl. R¹ may be R¹⁰-substituted 3 membered cycloalkyl. R¹may be R¹⁰-substituted or unsubstituted 4 membered cycloalkyl. R¹ may beR¹⁰-substituted 4 membered cycloalkyl. R¹ may be R¹⁰-substituted orunsubstituted 5 membered cycloalkyl. R¹ may be R¹⁰-substituted 5membered cycloalkyl. R¹ may be R¹⁰-substituted or unsubstituted 6membered cycloalkyl. R¹ may be R¹⁰-substituted 6 membered cycloalkyl.

R¹ may be substituted or unsubstituted 3 to 10 memberedheterocycloalkyl. R¹ may be substituted 3 to 10 memberedheterocycloalkyl. R¹ may be unsubstituted 3 to 10 memberedheterocycloalkyl. R¹ may be substituted or unsubstituted 3 to 6 memberedheterocycloalkyl. R¹ may be substituted 3 to 6 memberedheterocycloalkyl. R¹ may be unsubstituted 3 to 6 memberedheterocycloalkyl. R¹ may be substituted or unsubstituted 3 to 5 memberedheterocycloalkyl. R¹ may be substituted 3 to 5 memberedheterocycloalkyl. R¹ may be unsubstituted 3 to 5 memberedheterocycloalkyl. R¹ may be substituted or unsubstituted 3 memberedheterocycloalkyl. R¹ may be substituted 3 membered heterocycloalkyl. R¹may be unsubstituted 3 membered heterocycloalkyl. R¹ may be substitutedor unsubstituted 4 membered heterocycloalkyl. R¹ may be substituted 4membered heterocycloalkyl. R¹ may be unsubstituted 4 memberedheterocycloalkyl. R¹ may be substituted or unsubstituted 5 memberedheterocycloalkyl. R¹ may be substituted 5 membered heterocycloalkyl. R¹may be unsubstituted 5 membered heterocycloalkyl. R¹ may be substitutedor unsubstituted 6 membered heterocycloalkyl. R¹ may be substituted 6membered heterocycloalkyl. R¹ may be unsubstituted 6 memberedheterocycloalkyl.

R¹ may be R¹⁰-substituted or unsubstituted 3 to 10 memberedheterocycloalkyl. R¹ may be R¹⁰-substituted 3 to 10 memberedheterocycloalkyl. R¹ may be R¹⁰-substituted or unsubstituted 3 to 6membered heterocycloalkyl. R¹ may be R¹⁰-substituted 3 to 6 memberedheterocycloalkyl. R¹ may be R¹⁰-substituted or unsubstituted 3 to 5membered heterocycloalkyl. R¹ may be R¹⁰-substituted 3 to 5 memberedheterocycloalkyl. R¹ may be R¹⁰-substituted or unsubstituted 3 memberedheterocycloalkyl. R¹ may be R¹⁰-substituted 3 membered heterocycloalkyl.R¹ may be R¹⁰-substituted or unsubstituted 4 membered heterocycloalkyl.R¹ may be R¹⁰-substituted 4 membered heterocycloalkyl. R¹ may beR¹⁰-substituted or unsubstituted 5 membered heterocycloalkyl. R¹ may beR¹⁰-substituted 5 membered heterocycloalkyl. R¹ may be R¹⁰-substitutedor unsubstituted 6 membered heterocycloalkyl. R¹ may be R¹⁰-substituted6 membered heterocycloalkyl.

R¹ may be substituted or unsubstituted aryl. R¹ may be substituted aryl.R¹ may be unsubstituted aryl. R¹ may be substituted or unsubstituted 5to 10 membered aryl. R¹ may be substituted 5 to 10 membered aryl. R¹ maybe unsubstituted 5 to 10 membered aryl. R¹ may be substituted orunsubstituted 5 or 6 membered aryl. R¹ may be substituted 5 or 6membered aryl. R¹ may be unsubstituted 5 or 6 membered aryl. R¹ may besubstituted or unsubstituted 5 membered aryl. R¹ may be substituted 5membered aryl. R¹ may be unsubstituted 5 membered aryl. R¹ may besubstituted or unsubstituted 6 membered aryl. R¹ may be substituted 6membered aryl. R¹ may be unsubstituted 6 membered aryl.

R¹ may be R¹⁰-substituted or unsubstituted aryl. R¹ may beR¹⁰-substituted aryl. R¹ may be R¹⁰-substituted or unsubstituted 5 to 10membered aryl. R¹ may be R¹⁰-substituted 5 to 10 membered aryl. R¹ maybe R¹⁰-substituted or unsubstituted 5 or 6 membered aryl. R¹ may beR¹⁰-substituted 5 or 6 membered aryl. R¹ may be R¹⁰-substituted orunsubstituted 5 membered aryl. R¹ may be R¹⁰-substituted 5 memberedaryl. R¹ may be R¹⁰-substituted or unsubstituted 6 membered aryl. R¹ maybe R¹⁰-substituted 6 membered aryl.

R¹ may be substituted or unsubstituted heteroaryl. R¹ may be substitutedheteroaryl. R¹ may be unsubstituted heteroaryl. R¹ may be substituted orunsubstituted 5 to 10 membered heteroaryl. R¹ may be substituted 5 to 10membered heteroaryl. R¹ may be unsubstituted 5 to 10 memberedheteroaryl. R¹ may be substituted or unsubstituted 5 or 6 memberedheteroaryl. R¹ may be substituted 5 or 6 membered heteroaryl. R¹ may beunsubstituted 5 or 6 membered heteroaryl. R¹ may be substituted orunsubstituted 5 membered heteroaryl. R¹ may be substituted 5 memberedheteroaryl. R¹ may be unsubstituted 5 membered heteroaryl. R¹ may besubstituted or unsubstituted 6 membered heteroaryl. R¹ may besubstituted 6 membered heteroaryl. R¹ may be unsubstituted 6 memberedheteroaryl.

R¹ may be R¹⁰-substituted or unsubstituted heteroaryl. R¹ may beR¹⁰-substituted heteroaryl. R¹ may be R¹⁰-substituted or unsubstituted 5to 10 membered heteroaryl. R¹ may be R¹⁰-substituted 5 to 10 memberedheteroaryl. R¹ may be R¹⁰-substituted or unsubstituted 5 or 6 memberedheteroaryl. R¹ may be R¹⁰-substituted 5 or 6 membered heteroaryl. R¹ maybe R¹⁰-substituted or unsubstituted 5 membered heteroaryl. R¹ may beR¹⁰-substituted 5 membered heteroaryl. R¹ may be R¹⁰-substituted orunsubstituted 6 membered heteroaryl. R¹ may be R¹⁰-substituted 6membered heteroaryl.

R¹⁰ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R¹¹-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R¹¹-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R¹¹-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R¹¹-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R¹¹-substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or R¹-substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl. R¹⁰ may be hydrogen, halogen, oxo, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, substituted orunsubstituted (e.g. C₁-C₅) alkyl, substituted or unsubstituted (e.g. 2to 5 membered) heteroalkyl, substituted or unsubstituted (e.g. C₃-C₈)cycloalkyl, substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl. R¹⁰ may be hydrogen, halogen, oxo, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g.C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5 membered) heteroalkyl,unsubstituted (e.g. C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8membered) heterocycloalkyl, unsubstituted aryl (e.g. phenyl ornaphthyl), or unsubstituted (e.g. 5 or 6 membered or fused ring)heteroaryl.

R¹¹ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R¹²-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R¹²-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R¹²-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R¹²-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R¹²-substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or R¹²-substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl.

R¹² is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R¹³-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R¹³-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R¹³-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R¹³-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R¹³-substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or R¹³-substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl.

R¹³ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g. C₁-C₅) alkyl,unsubstituted (e.g. 2 to 5 membered) heteroalkyl, unsubstituted (e.g.C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, unsubstituted aryl (e.g. phenyl or naphthyl), orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

The symbol m1 may be 0, 1, 2, or 3. The symbol m1 may be 0. The symbolm1 may be 1. The symbol m1 may be 2. The symbol m1 may be 3. The symbolm1 may be 1, 2, or 3. When R¹ is halogen, the symbol m1 may be 1. WhenR¹ is —CF₃ the symbol m1 may be 1, 2, or 3. R¹ may independently behalogen or —CF₃ and the symbol m1 is 2 or 3. When R¹ is —OR^(1A), thesymbol m1 may be 1, 2, or 3. When R¹ is —OCH₃ the symbol m1 may be 1, 2,or 3. When R¹ is —OCH₃ the symbol m1 may be 1. When R¹ is —OCH₃ thesymbol m1 may be 2. When R¹ is —OCH₃ the symbol m1 may be 3.

R^(1A) and R^(1B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, —ONH₂, —NHC(O)NHNH₂,substituted or unsubstituted alkyl, substituted or unsubstitutedheteroalkyl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted heterocycloalkyl, substituted or unsubstituted aryl, orsubstituted or unsubstituted heteroaryl. R^(1A) and R^(1B) mayindependently be hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂, —COOH,—CONH₂, —NO₂, —SH, —S(O)₃H, —ONH₂, —NHC(O)NHNH₂, R¹⁰-substituted orunsubstituted (e.g. C₁-C₅) alkyl, R¹⁰-substituted or unsubstituted (e.g.2 to 5 membered) heteroalkyl, R¹⁰-substituted or unsubstituted (e.g.C₃-C₈) cycloalkyl, R¹⁰-substituted or unsubstituted (e.g. 3 to 8membered) heterocycloalkyl, R¹⁰-substituted or unsubstituted aryl (e.g.phenyl or naphthyl), or R¹⁰-substituted or unsubstituted (e.g. 5 or 6membered or fused ring) heteroaryl.

R^(1A) and R^(1B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, or —ONH₂. R^(1A) andR^(1B) may independently be substituted or unsubstituted alkyl,substituted or unsubstituted heteroalkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heterocycloalkyl, substitutedor unsubstituted aryl, or substituted or unsubstituted heteroaryl.R^(1A) and R^(1B) may independently be R^(1C)-substituted orunsubstituted (e.g. C₁-C₅) alkyl, R^(1C)-substituted or unsubstituted(e.g. 2 to 5 membered) heteroalkyl, R^(1C)-substituted or unsubstituted(e.g. C₃-C₈) cycloalkyl, R^(1C)-substituted or unsubstituted (e.g. 3 to8 membered) heterocycloalkyl, R^(1C)-substituted or unsubstituted aryl(e.g. phenyl or naphthyl), or R^(1C)-substituted or unsubstituted (e.g.5 or 6 membered or fused ring) heteroaryl.

R^(1C) is hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂, —ONH₂,—NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH, —OCF₃,—OCHF₂, unsubstituted (e.g. C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5membered) heteroalkyl, unsubstituted (e.g. C₃-C₈) cycloalkyl,unsubstituted (e.g. 3 to 8 membered) heterocycloalkyl, unsubstitutedaryl (e.g. phenyl or naphthyl), or unsubstituted (e.g. 5 or 6 memberedor fused ring) heteroaryl.

R² may be halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(2A),—C(O)R^(2A), —NR^(2A)R^(2B), —C(O)OR^(2A), —C(O)NR^(2A)R^(2B), —NO₂,—SR^(2A), —S(O)_(n2)R^(2A), —S(O)_(n2)OR^(2A), —S(O)_(n2)NR^(2A)R^(2B),—NHNR^(2A)R^(2B), —ONR^(2A)R^(2B), or —NHC(O)NHNR^(2A)R^(2B). R² may behalogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(2A), —NR^(2A)R^(2B),—NO₂, or —SR^(2A). R² may be halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃,—CN, —OR^(2A), —C(O)R^(2A), —NR^(2A)R^(2B), —C(O)OH, —NO₂, or —SH. R²may be halogen, —CF₃, —CCl₃, —CBr₃, —CI₃, —OR^(2A), —NH₂, —N(CH₃)₂—NO₂.R² may be halogen, —CF₃, —OR^(2A), or —NO₂. R² may be halogen. R² may be—CF₃. R² may be —OR^(2A). R² may be —NO₂. R² may be —OR^(2A), whereR^(2A) is substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, or substituted or unsubstituted aryl. R² maybe —OR^(2A), where R^(2A) is substituted or unsubstituted alkyl. R² maybe —OR^(2A), where R^(2A) is substituted or unsubstituted C₁-C₅ alkyl.R² may be —OR^(2A), where R^(2A) is substituted or unsubstituted C₁-C₃alkyl. R² may be —OR^(2A), where R^(2A) is methyl. R² may be halogen,—CF₃, —OR^(2A), —NO₂, substituted or unsubstituted C₁-C₅ alkyl, orsubstituted or unsubstituted 2 to 5 membered heteroalkyl.

R² may be substituted or unsubstituted C₁-C₅ alkyl, or substituted orunsubstituted 2 to 5 membered heteroalkyl. R² may be substituted orunsubstituted C₁-C₅ alkyl. R² may be substituted C₁-C₅ alkyl. R² may beunsubstituted C₁-C₅ alkyl. R² may be substituted or unsubstituted C₁-C₃alkyl. R² may be substituted C₁-C₃ alkyl. R² may be unsubstituted C₁-C₃alkyl. R² may be methyl. R² may be ethyl. R² may be propyl.

R² may be R²⁰-substituted or unsubstituted C₁-C₅ alkyl. R² may beR²⁰-substituted or unsubstituted C₁-C₅ alkyl. R² may be R²⁰-substitutedC₁-C₅ alkyl. R² may be R²⁰-substituted or unsubstituted C₁-C₃ alkyl. R²may be R²⁰-substituted C₁-C₃ alkyl.

R² may be substituted or unsubstituted 2 to 5 membered heteroalkyl. R²may be substituted 2 to 5 membered heteroalkyl. R² may be unsubstituted2 to 5 membered heteroalkyl. R² may be R²⁰-substituted or unsubstituted2 to 5 membered heteroalkyl. R² may be R²⁰-substituted 2 to 5 memberedheteroalkyl.

R²⁰ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g. C₁-C₅) alkyl,unsubstituted (e.g. 2 to 5 membered) heteroalkyl, unsubstituted (e.g.C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, unsubstituted aryl (e.g. phenyl or naphthyl), orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

R^(2A) and R^(2B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, —ONH₂, —NHC(O)NHNH₂,substituted or unsubstituted alkyl, substituted or unsubstitutedheteroalkyl, substituted or unsubstituted cycloalkyl, substituted orunsubstituted heterocycloalkyl, substituted or unsubstituted aryl, orsubstituted or unsubstituted heteroaryl. R^(2A) and R^(2B) mayindependently be hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂, —COOH,—CONH₂, —NO₂, —SH, —S(O)₃H, —ONH₂, —NHC(O)NHNH₂, R²⁰-substituted orunsubstituted (e.g. C₁-C₅) alkyl, R²⁰-substituted or unsubstituted (e.g.2 to 5 membered) heteroalkyl, R²⁰-substituted or unsubstituted (e.g.C₃-C₈) cycloalkyl, R²⁰-substituted or unsubstituted (e.g. 3 to 8membered) heterocycloalkyl, R²⁰-substituted or unsubstituted aryl (e.g.phenyl or naphthyl), or R²⁰-substituted or unsubstituted (e.g. 5 or 6membered or fused ring) heteroaryl.

R^(2A) and R^(2B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, or —ONH₂. R^(2A) andR^(2B) may independently be substituted or unsubstituted alkyl,substituted or unsubstituted heteroalkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heterocycloalkyl, substitutedor unsubstituted aryl, or substituted or unsubstituted heteroaryl.R^(2A) and R^(2B) may independently be R^(2C)-substituted orunsubstituted (e.g. C₁-C₅) alkyl, R^(2C)-substituted or unsubstituted(e.g. 2 to 5 membered) heteroalkyl, R^(2C)-substituted or unsubstituted(e.g. C₃-C₈) cycloalkyl, R^(2C)-substituted or unsubstituted (e.g. 3 to8 membered) heterocycloalkyl, R^(2C)-substituted or unsubstituted aryl(e.g. phenyl or naphthyl), or R^(2C)-substituted or unsubstituted (e.g.5 or 6 membered or fused ring) heteroaryl.

R^(2C) is hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂, —ONH₂,—NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH, —OCF₃,—OCHF₂, unsubstituted (e.g. C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5membered) heteroalkyl, unsubstituted (e.g. C₃-C₈) cycloalkyl,unsubstituted (e.g. 3 to 8 membered) heterocycloalkyl, unsubstitutedaryl (e.g. phenyl or naphthyl), or unsubstituted (e.g. 5 or 6 memberedor fused ring) heteroaryl.

R³ may be hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —C(O)H,—OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂,or —NHC(O)NHNH₂. R³ may be hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, or —ONH₂. R³ may be hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, or —SH. R³ may behydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OCH₃, —OCH₂CH₃,—NH₂, or —NO₂. R³ may be hydrogen, halogen, or —OR^(3A). R³ may behydrogen, halogen, —CF₃, —OCH₃, —OCH₂CH₃, —NH₂, or —NO₂. R³ may behalogen. R³ may be hydrogen. R³ may be —CF₃. R³ may be —OCH₃. R³ may be—OCH₂CH₃. R³ may be —NH₂. R³ may be —NO₂.

R³ may be substituted or unsubstituted C₁-C₅ alkyl, or substituted orunsubstituted 2 to 5 membered heteroalkyl. R³ may be substituted orunsubstituted C₁-C₅ alkyl. R³ may be substituted C₁-C₅ alkyl. R³ may beunsubstituted C₁-C₅ alkyl. R³ may be substituted or unsubstituted C₁-C₃alkyl. R³ may be substituted C₁-C₃ alkyl. R³ may be unsubstituted C₁-C₃alkyl. R³ may be methyl. R³ may be ethyl. R³ may be propyl.

R³ may be R³⁰-substituted or unsubstituted C₁-C₅ alkyl. R³ may beR³⁰-substituted or unsubstituted C₁-C₅ alkyl. R³ may be R³⁰-substitutedC₁-C₅ alkyl. R³ may be R³⁰-substituted or unsubstituted C₁-C₃ alkyl. R³may be R³⁰-substituted C₁-C₃ alkyl.

R³ may be substituted or unsubstituted 2 to 5 membered heteroalkyl. R³may be substituted 2 to 5 membered heteroalkyl. R³ may be unsubstituted2 to 5 membered heteroalkyl. R³ may be R³⁰-substituted or unsubstituted2 to 5 membered heteroalkyl. R³ may be R³⁰-substituted 2 to 5 memberedheteroalkyl.

R³⁰ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g. C₁-C₅) alkyl,unsubstituted (e.g. 2 to 5 membered) heteroalkyl, unsubstituted (e.g.C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, unsubstituted aryl (e.g. phenyl or naphthyl), orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

The symbol m3 may be 1. The symbol m3 may be 2. When R³ is halogen, thesymbol m3 may be 1. When R³ is —CF₃, the symbol m3 may be 1. When R³ is—OCH₃ or —OCH₂CH₃, the symbol m3 may be 1. When R³ is —OCH₃ or —OCH₂CH₃,the symbol m3 may be 2. R³ may independently be halogen and —OCH₃ andthe symbol m3 is 2.

X may be —C(R⁴)═. X may be —N═.

When X is —C(R⁴)═, R⁴ may be hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(4A), —C(O)R^(4A), —NR^(4A)R^(4B), —C(O)OR^(4A),—C(O)NR^(4A)R^(4B), —NO₂, —SR^(4A), —S(O)_(n4)R^(4A), —S(O)_(n4)OR^(4A),—S(O)_(n4)NR^(4A)R^(4B), —NHNR^(4A)R^(4B), —ONR^(4A)R^(4B), or—NHC(O)NHNR^(4A)R⁴. R⁴ may be hydrogen, halogen, —OR^(4A), or—C(O)R^(4A). R⁴ may be hydrogen or halogen. R⁴ may be hydrogen. R⁴ maybe halogen.

R⁴ may be substituted or unsubstituted C₁-C₅ alkyl, or substituted orunsubstituted 2 to 5 membered heteroalkyl. R⁴ may be substituted orunsubstituted C₁-C₅ alkyl. R⁴ may be substituted C₁-C₅ alkyl. R⁴ may beunsubstituted C₁-C₅ alkyl. R⁴ may be substituted or unsubstituted C₁-C₃alkyl. R⁴ may be substituted C₁-C₃ alkyl. R⁴ may be unsubstituted C₁-C₃alkyl. R⁴ may be methyl. R⁴ may be ethyl. R⁴ may be propyl.

R⁴ may be R⁴⁰-substituted or unsubstituted C₁-C₅ alkyl. R⁴ may beR⁴⁰-substituted or unsubstituted C₁-C₅ alkyl. R⁴ may be R⁴⁰-substitutedC₁-C₅ alkyl. R⁴ may be R⁴⁰-substituted or unsubstituted C₁-C₃ alkyl. R⁴may be R⁴⁰-substituted C₁-C₃ alkyl.

R⁴ may be substituted or unsubstituted 2 to 5 membered heteroalkyl. R⁴may be substituted 2 to 5 membered heteroalkyl. R⁴ may be unsubstituted2 to 5 membered heteroalkyl. R⁴ may be R⁴⁰-substituted or unsubstituted2 to 5 membered heteroalkyl. R⁴ may be R⁴⁰-substituted 2 to 5 memberedheteroalkyl.

R⁴⁰ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g. C₁-C₅) alkyl,unsubstituted (e.g. 2 to 5 membered) heteroalkyl, unsubstituted (e.g.C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, unsubstituted aryl (e.g. phenyl or naphthyl), orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl. R^(4A)and R^(4B) may independently be hydrogen, oxo, halogen, —CF₃, —CN, —OH,—NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, —ONH₂, —NHC(O)NHNH₂,R⁴⁰-substituted or unsubstituted (e.g. C₁-C₅) alkyl, R⁴⁰-substituted orunsubstituted (e.g. 2 to 5 membered) heteroalkyl, R⁴⁰-substituted orunsubstituted (e.g. C₃-C₈) cycloalkyl, R⁴⁰-substituted or unsubstituted(e.g. 3 to 8 membered) heterocycloalkyl, R⁴⁰-substituted orunsubstituted aryl (e.g. phenyl or naphthyl), or R⁴⁰-substituted orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

R^(4A) and R^(4B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, or —ONH₂. R^(4A) andR^(4B) may independently be substituted or unsubstituted alkyl,substituted or unsubstituted heteroalkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heterocycloalkyl, substitutedor unsubstituted aryl, or substituted or unsubstituted heteroaryl.R^(4A) and R^(4B) may independently be R^(4C)-substituted orunsubstituted (e.g. C₁-C₅) alkyl, R^(4C)-substituted or unsubstituted(e.g. 2 to 5 membered) heteroalkyl, R^(4C)-substituted or unsubstituted(e.g. C₃-C₈) cycloalkyl, R^(4C)-substituted or unsubstituted (e.g. 3 to8 membered) heterocycloalkyl, R^(4C)-substituted or unsubstituted aryl(e.g. phenyl or naphthyl), or R^(4C)-substituted or unsubstituted (e.g.5 or 6 membered or fused ring) heteroaryl.

R^(4C) is hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂, —ONH₂,—NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH, —OCF₃,—OCHF₂, unsubstituted (e.g. C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5membered) heteroalkyl, unsubstituted (e.g. C₃-C₈) cycloalkyl,unsubstituted (e.g. 3 to 8 membered) heterocycloalkyl, unsubstitutedaryl (e.g. phenyl or naphthyl), or unsubstituted (e.g. 5 or 6 memberedor fused ring) heteroaryl.

Y may be a bond or —N(R⁵)—. Y may be a bond or —O—. Y may be a bond or—S—. Y may be a bond, —N(R⁵)—, or —S—. Y may be a bond. Y may be —O—. Ymay be —S—. Y may be —N(R⁵)—.

When Y is —N(R⁵)—, R⁵ may be hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(5A), —C(O)R^(5A), —NR^(5A)R^(5B), —C(O)OR^(5A),—C(O)NR^(5A)R^(5B), —NO₂, —SR^(5A), —S(O)_(n5)R^(5A), —S(O)_(n5)OR^(5A),—S(O)_(n5)NR^(5A)R^(5B), —NHNR^(5A)R^(5B), —ONR^(5A)R^(5B), or—NHC(O)NHNR^(5A)R^(5B). R⁵ may be hydrogen, halogen, —N₃, —CF₃, —CCl₃,—CBr₃, —CI₃, —CN, —OR^(5A), —NR^(5A)R^(5B), —C(O)OR^(5A),—C(O)NR^(5A)R^(5B), —NO₂, or —SR^(5A). R⁵ may be hydrogen, halogen, —N₃,—CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(5A), —NR^(5A)R^(5B), —C(O)OR^(5A),—NO₂, or —SR^(5A). R⁵ may be hydrogen, halogen, —CF₃, —CN, —OR^(5A),—NR^(5A)R^(5B), —NO₂, or —SR^(5A). R⁵ may be hydrogen, halogen, —CF₃,—CN, —OR^(5A), —NH₂, —NO₂, or —SH. R⁵ may be hydrogen. R⁵ may behalogen. R⁵ may be —CF₃. R⁵ may be —CN. R⁵ may be —OR^(5A). R⁵ may be—NR^(5A)R^(5B). R⁵ may be, —NO₂. R⁵ may be —SR^(5A).

R⁵ may be substituted or unsubstituted C₁-C₅ alkyl, or substituted orunsubstituted 2 to 5 membered heteroalkyl. R⁵ may be substituted orunsubstituted C₁-C₅ alkyl. R⁵ may be substituted C₁-C₅ alkyl. R⁵ may beunsubstituted C₁-C₅ alkyl. R⁵ may be substituted or unsubstituted C₁-C₃alkyl. R⁵ may be substituted C₁-C₃ alkyl. R⁵ may be unsubstituted C₁-C₃alkyl. R⁵ may be methyl. R⁵ may be ethyl. R⁵ may be propyl.

R⁵ may be R⁵⁰-substituted or unsubstituted C₁-C₅ alkyl. R⁵ may beR⁵⁰-substituted or unsubstituted C₁-C₅ alkyl. R⁵ may be R⁵⁰-substitutedC₁-C₅ alkyl. R⁵ may be R⁵⁰-substituted or unsubstituted C₁-C₃ alkyl. R⁵may be R⁵⁰-substituted C₁-C₃ alkyl.

R⁵ may be substituted or unsubstituted 2 to 5 membered heteroalkyl. R⁵may be substituted 2 to 5 membered heteroalkyl. R⁵ may be unsubstituted2 to 5 membered heteroalkyl. R⁵ may be R⁵⁰-substituted or unsubstituted2 to 5 membered heteroalkyl. R⁵ may be R⁵-substituted 2 to 5 memberedheteroalkyl.

R⁵⁰ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g. C₁-C₅) alkyl,unsubstituted (e.g. 2 to 5 membered) heteroalkyl, unsubstituted (e.g.C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, unsubstituted aryl (e.g. phenyl or naphthyl), orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

R^(5A) and R^(5B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, or —ONH₂. R^(5A) andR^(5B) may independently be substituted or unsubstituted alkyl,substituted or unsubstituted heteroalkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heterocycloalkyl, substitutedor unsubstituted aryl, or substituted or unsubstituted heteroaryl.R^(5A) and R^(5B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, —ONH₂, —NHC(O)NHNH₂,R⁵⁰-substituted or unsubstituted (e.g. C₁-C₅) alkyl, R⁵⁰-substituted orunsubstituted (e.g. 2 to 5 membered) heteroalkyl, R⁵⁰-substituted orunsubstituted (e.g. C₃-C₈) cycloalkyl, R⁵⁰-substituted or unsubstituted(e.g. 3 to 8 membered) heterocycloalkyl, R⁵-substituted or unsubstitutedaryl (e.g. phenyl or naphthyl), or R⁵⁰-substituted or unsubstituted(e.g. 5 or 6 membered or fused ring) heteroaryl.

R^(5A) and R^(5B) may independently be R^(5C)-substituted orunsubstituted (e.g. C₁-C₅) alkyl, R^(5C)-substituted or unsubstituted(e.g. 2 to 5 membered) heteroalkyl, R^(5C)-substituted or unsubstituted(e.g. C₃-C₈) cycloalkyl, R^(5C)-substituted or unsubstituted (e.g. 3 to8 membered) heterocycloalkyl, R^(5C)-substituted or unsubstituted aryl(e.g. phenyl or naphthyl), or R^(5C)-substituted or unsubstituted (e.g.5 or 6 membered or fused ring) heteroaryl.

R^(5C) is hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂, —ONH₂,—NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH, —OCF₃,—OCHF₂, unsubstituted (e.g. C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5membered) heteroalkyl, unsubstituted (e.g. C₃-C₈) cycloalkyl,unsubstituted (e.g. 3 to 8 membered) heterocycloalkyl, unsubstitutedaryl (e.g. phenyl or naphthyl), or unsubstituted (e.g. 5 or 6 memberedor fused ring) heteroaryl.

L¹ may be a bond, —C(O)—, —O—, —S—, —N(R⁶)—, —C(O)N(R⁶)—, —S(O)_(n6)—,substituted or unsubstituted alkylene, substituted or unsubstitutedheteroalkylene, substituted or unsubstituted cycloalkylene, substitutedor unsubstituted heterocycloalkylene, substituted or unsubstitutedarylene, or substituted or unsubstituted heteroarylene. L¹ may be abond, —C(O)—, —O—, —S—, —NH—, —C(O)NH—, —S(O)₂—, substituted orunsubstituted alkylene, substituted or unsubstituted heteroalkylene,substituted or unsubstituted cycloalkylene, substituted or unsubstitutedheterocycloalkylene, substituted or unsubstituted arylene, orsubstituted or unsubstituted heteroarylene. L¹ may be a bond, —C(O)—,—O—, —NH—, substituted or unsubstituted alkylene, substituted orunsubstituted heteroalkylene, substituted or unsubstitutedcycloalkylene, substituted or unsubstituted heterocycloalkylene,substituted or unsubstituted arylene, or substituted or unsubstitutedheteroarylene.

L¹ may be a bond, —C(O)—, —O—, —S—, —N(R⁶)—, —C(O)N(R⁶)—, or—S(O)_(n6)—. L¹ may be a bond, —C(O)—, —O—, —S—, —NH—, —C(O)NH—, or—S(O)₂—. L¹ may be a bond. L¹ may be —C(O). L¹ may be —O—. L¹ may be—S—. L¹ may —N(R⁶)—. L¹ may be —C(O)N(R⁶). L¹ may be —S(O)_(n6)—.

L¹ may be substituted or unsubstituted alkylene, substituted orunsubstituted heteroalkylene, substituted or unsubstitutedcycloalkylene, substituted or unsubstituted heterocycloalkylene,substituted or unsubstituted arylene, or substituted or unsubstitutedheteroarylene.

L¹ may be substituted or unsubstituted alkylene. L¹ may be substitutedalkylene. L¹ may be unsubstituted alkylene. L¹ may be substituted orunsubstituted C₁-C₂₀ alkylene. L¹ may be substituted C₁-C₂₀ alkylene. L¹may be substituted or unsubstituted C₁-C₁₀ alkylene. L¹ may besubstituted C₁-C₁₀ alkylene. L¹ may be unsubstituted C₁-C₁₀ alkylene. L¹may be substituted or unsubstituted C₁-C₅ alkylene. L¹ may besubstituted C₁-C₅ alkylene. L¹ may be unsubstituted C₁-C₅ alkylene.

L¹ may be R¹⁴-substituted or unsubstituted alkylene. L¹ may beR¹⁴-substituted alkylene. L¹ may be R¹⁴-substituted or unsubstitutedC₁-C₂₀ alkylene. L¹ may be R¹⁴-substituted C₁-C₂₀ alkylene. L¹ may beR¹⁴-substituted or unsubstituted C₁-C₁₀ alkylene. L¹ may beR¹⁴-substituted C₁-C₁₀ alkylene. L¹ may be R¹⁴-substituted orunsubstituted C₁-C₅ alkylene. L¹ may be R¹⁴-substituted C₁-C₅ alkylene.

L¹ may be substituted or unsubstituted heteroalkylene. L¹ may besubstituted heteroalkylene. L¹ may be unsubstituted heteroalkylene. L¹may be substituted or unsubstituted 2 to 20 membered heteroalkylene. L¹may be substituted 2 to 20 membered heteroalkylene. L¹ may beunsubstituted 2 to 20 membered heteroalkylene. L¹ may be substituted orunsubstituted 2 to 10 membered heteroalkylene. L¹ may be substituted 2to 10 membered heteroalkylene. L¹ may be unsubstituted 2 to 10 memberedheteroalkylene. L¹ may be substituted or unsubstituted 2 to 5 memberedheteroalkylene. L¹ may be substituted 2 to 5 membered heteroalkylene. L¹may be unsubstituted 2 to 5 membered heteroalkylene.

L¹ may be R¹⁴-substituted or unsubstituted heteroalkylene. L¹ may beR¹⁴-substituted heteroalkylene. L¹ may be R¹⁴-substituted orunsubstituted 2 to 20 membered heteroalkylene. L¹ may be R¹⁴-substituted2 to 20 membered heteroalkylene. L¹ may be R¹⁴-substituted orunsubstituted 2 to 10 membered heteroalkylene. L¹ may be R¹⁴-substituted2 to 10 membered heteroalkylene. L¹ may be R¹⁴-substituted orunsubstituted 2 to 5 membered heteroalkylene. L¹ may be R¹⁴-substituted2 to 5 membered heteroalkylene.

L¹ may be substituted or unsubstituted cycloalkylene. L¹ may besubstituted cycloalkylene. L¹ may be unsubstituted cycloalkylene. L¹ maybe substituted or unsubstituted 3 to 10 membered cycloalkylene. L¹ maybe substituted 3 to 10 membered cycloalkylene. L¹ may be unsubstituted 3to 10 membered cycloalkylene. L¹ may be substituted or unsubstituted 3to 6 membered cycloalkylene. L¹ may be substituted 3 to 6 memberedcycloalkylene. L¹ may be unsubstituted 3 to 6 membered cycloalkylene. L¹may be substituted or unsubstituted 3 membered cycloalkylene. L¹ may besubstituted or unsubstituted 4 membered cycloalkylene. L¹ may besubstituted or unsubstituted 5 membered cycloalkylene. L¹ may besubstituted or unsubstituted 6 membered cycloalkylene.

L¹ may be R¹⁴-substituted or unsubstituted cycloalkylene. L¹ may beR¹⁴-substituted cycloalkylene. L¹ may be R¹⁴-substituted orunsubstituted 3 to 10 membered cycloalkylene. L¹ may be R¹⁴-substituted3 to 10 membered cycloalkylene. L¹ may be R¹⁴-substituted orunsubstituted 3 to 6 membered cycloalkylene. L¹ may be R¹⁴-substituted 3to 6 membered cycloalkylene. L¹ may be R¹⁴-substituted or unsubstituted3 membered cycloalkylene. L¹ may be R¹⁴-substituted or unsubstituted 4membered cycloalkylene. L¹ may be R¹⁴-substituted or unsubstituted 5membered cycloalkylene. L¹ may be R¹⁴-substituted or unsubstituted 6membered cycloalkylene.

L¹ may be substituted or unsubstituted heterocycloalkylene. L¹ may besubstituted heterocycloalkylene. L¹ may be unsubstitutedheterocycloalkylene. L¹ may be substituted or unsubstituted 3 to 10membered heterocycloalkylene. L¹ may be substituted 3 to 10 memberedheterocycloalkylene. L¹ may be unsubstituted 3 to 10 memberedheterocycloalkylene. L¹ may be substituted or unsubstituted 3 to 6membered heterocycloalkylene. L¹ may be substituted 3 to 6 memberedheterocycloalkylene. L¹ may be unsubstituted 3 to 6 memberedheterocycloalkylene. L¹ may be substituted or unsubstituted 3 memberedheterocycloalkylene. L¹ may be substituted or unsubstituted 4 memberedheterocycloalkylene. L¹ may be substituted or unsubstituted 5 memberedheterocycloalkylene. L¹ may be substituted or unsubstituted 6 memberedheterocycloalkylene.

L¹ may be R¹⁴-substituted or unsubstituted heterocycloalkylene. L¹ maybe R¹⁴-substituted heterocycloalkylene. L¹ may be R¹⁴-substituted orunsubstituted 3 to 10 membered heterocycloalkylene. L¹ may beR¹⁴-substituted 3 to 10 membered heterocycloalkylene. L¹ may beR¹⁴-substituted or unsubstituted 3 to 6 membered heterocycloalkylene. L¹may be R¹⁴-substituted 3 to 6 membered heterocycloalkylene. L¹ may beR¹⁴-substituted or unsubstituted 3 membered heterocycloalkylene. L¹ maybe R¹⁴-substituted or unsubstituted 4 membered heterocycloalkylene. L¹may be R¹⁴-substituted or unsubstituted 5 membered heterocycloalkylene.L¹ may be R¹⁴-substituted or unsubstituted 6 memberedheterocycloalkylene.

L¹ may be substituted or unsubstituted arylene. L¹ may be substitutedarylene. L¹ may be unsubstituted arylene. L¹ may be substituted orunsubstituted 5 to 10 membered arylene. L¹ may be substituted 5 to 10membered arylene. L¹ may be unsubstituted 5 to 10 membered arylene. L¹may be substituted or unsubstituted 5 membered arylene. L¹ may besubstituted 5 membered arylene. L¹ may be unsubstituted 5 memberedarylene. L¹ may be substituted or unsubstituted 6 membered arylene. L¹may be substituted 6 membered arylene. L¹ may be unsubstituted 6membered arylene (e.g. phenylene).

L¹ may be R¹⁴-substituted or unsubstituted arylene. L¹ may beR¹⁴-substituted arylene. L¹ may be R¹⁴-substituted or unsubstituted 5 to10 membered arylene. L¹ may be R¹⁴-substituted 5 to 10 membered arylene.L¹ may be R¹⁴-substituted or unsubstituted 5 membered arylene. L¹ may beR¹⁴-substituted 5 membered arylene. L¹ may be R¹⁴-substituted orunsubstituted 6 membered arylene. L¹ may be R¹⁴-substituted 6 memberedarylene.

L¹ may be substituted or unsubstituted heteroarylene. L¹ may besubstituted heteroarylene. L¹ may be unsubstituted heteroarylene. L¹ maybe substituted or unsubstituted 5 to 10 membered heteroarylene. L¹ maybe substituted 5 to 10 membered heteroarylene. L¹ may be unsubstituted 5to 10 membered heteroarylene. L¹ may be substituted or unsubstituted 5membered heteroarylene. L¹ may be substituted 5 membered heteroarylene.L¹ may be unsubstituted 5 membered heteroarylene. L¹ may be substitutedor unsubstituted 6 membered heteroarylene. L¹ may be substituted 6membered heteroarylene. L¹ may be unsubstituted 6 memberedheteroarylene.

L¹ may be R¹⁴-substituted or unsubstituted heteroarylene. L¹ may beR¹⁴-substituted heteroarylene. L¹ may be R¹⁴-substituted orunsubstituted 5 to 10 membered heteroarylene. L¹ may be R¹⁴-substituted5 to 10 membered heteroarylene. L¹ may be R¹⁴-substituted orunsubstituted 5 membered heteroarylene. L¹ may be R¹⁴-substituted 5membered heteroarylene. L¹ may be R¹⁴-substituted or unsubstituted 6membered heteroarylene. L¹ may be R¹⁴-substituted 6 memberedheteroarylene.

R¹⁴ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R¹⁵-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R¹⁵-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R¹⁵-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R¹⁵-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R^(s1)-substituted or unsubstituted aryl (e.g. phenylor naphthyl), or R¹⁵-substituted or unsubstituted (e.g. 5 or 6 memberedor fused ring) heteroaryl. R¹⁴ may be hydrogen, halogen, oxo, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, substituted orunsubstituted (e.g. C₁-C₅) alkyl, substituted or unsubstituted (e.g. 2to 5 membered) heteroalkyl, substituted or unsubstituted (e.g. C₃-C₈)cycloalkyl, substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl. R¹⁴ may be hydrogen, halogen, oxo, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g.C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5 membered) heteroalkyl,unsubstituted (e.g. C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8membered) heterocycloalkyl, unsubstituted aryl (e.g. phenyl ornaphthyl), or unsubstituted (e.g. 5 or 6 membered or fused ring)heteroaryl.

R¹⁵ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R¹⁶-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R¹⁶-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R¹⁶-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R¹⁶-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R¹⁶-substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or R¹⁶-substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl.

R¹⁶ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R¹⁷-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R¹⁷-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R¹⁷-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R¹⁷-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R¹⁷-substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or R¹⁷-substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl.

R¹⁷ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g. C₁-C₅) alkyl,unsubstituted (e.g. 2 to 5 membered) heteroalkyl, unsubstituted (e.g.C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, unsubstituted aryl (e.g. phenyl or naphthyl), orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

When L¹ is —N(R⁶)—, —C(O)N(R⁶)—, or —S(O)N(R⁶)—, R⁶ may be hydrogen,halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(6A), —C(O)R^(6A),—NR^(6A)R^(6B), —C(O)OR^(6A), —C(O)NR^(6A)R^(6B), —NO₂, —SR^(6A),—S(O)_(n6)R^(6A), —S(O)_(n6)OR^(6A), —S(O)_(n6)NR^(6A)R^(6B),—NHNR^(6A)R^(6B), —ONR^(6A)R^(6B), or —NHC(O)NHNR^(6A)R^(6B). R⁶ may behydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(6A),—C(O)R^(6A), —NR^(6A)R^(6B), —C(O)OR^(6A), —C(O)NR^(6A)R^(6B), —NO₂,—SR^(6A), or —S(O)_(n6)R^(6A). R⁶ may be hydrogen, halogen, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —OR^(6A), —NR^(6A)R^(6B), —C(O)OR^(6A),—C(O)NR^(6A)R^(6B), —NO₂, or —SR^(6A). R⁶ may be hydrogen, halogen, —N₃,—CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(6A), —NR^(6A)R^(6B), —C(O)OR^(6A),—NO₂, or —SR^(6A). R⁶ may be hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(6A), —NR^(6A)R^(6B), or —NO₂. R⁶ may be hydrogen,halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(6A), or —NH₂. R⁶ maybe hydrogen. R⁶ may be halogen. R⁶ may be —N₃. R⁶ may be —CF₃. R⁶ may be—CN. R⁶ may be —OR^(6A). R⁶ may be —NH₂. R⁶ may be —NO₂.

R⁶ may be substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl.

R⁶ may be substituted or unsubstituted alkyl. R⁶ may be substitutedalkyl. R⁶ may be unsubstituted alkyl. R⁶ may be substituted orunsubstituted C₁-C₂₀ alkyl. R⁶ may be substituted C₁-C₂₀ alkyl. R⁶ maybe unsubstituted C₁-C₂₀ alkyl. R⁶ may be substituted or unsubstitutedC₁-C₁₀ alkyl. R⁶ may be substituted C₁-C₁₀ alkyl. R⁶ may beunsubstituted C₁-C₁₀ alkyl. R⁶ may be substituted or unsubstituted C₁-C₅alkyl. R⁶ may be substituted C₁-C₅ alkyl. R⁶ may be unsubstituted C₁-C₅alkyl. R⁶ may be substituted or unsubstituted C₁-C₃ alkyl. R⁶ may besubstituted C₁-C₃ alkyl. R⁶ may be unsubstituted C₁-C₃ alkyl. R⁶ may bemethyl. R⁶ may be ethyl. R⁶ may be propyl.

R⁶ may be R⁶⁰-substituted or unsubstituted alkyl. R⁶ may beR⁶⁰-substituted alkyl. R⁶ may be R⁶⁰-substituted or unsubstituted C₁-C₂₀alkyl. R⁶ may be R⁶⁰-substituted C₁-C₂₀ alkyl. R⁶ may be R⁶⁰-substitutedor unsubstituted C₁-C₁₀ alkyl. R⁶ may be R⁶⁰-substituted C₁-C₁₀ alkyl R⁶may be R⁶⁰-substituted or unsubstituted C₁-C₅ alkyl. R⁶ may beR⁶⁰-substituted C₁-C₅ alkyl. R⁶ may be R⁶⁰-substituted or unsubstitutedC₁-C₃ alkyl. R⁶ may be R⁶⁰-substituted C₁-C₃ alkyl.

R⁶ may be substituted or unsubstituted 2 to 20 membered heteroalkyl. R⁶may be substituted 2 to 20 membered heteroalkyl. R⁶ may be unsubstituted2 to 20 membered heteroalkyl. R⁶ may be substituted or unsubstituted 2to 10 membered heteroalkyl. R⁶ may be substituted 2 to 10 memberedheteroalkyl. R⁶ may be unsubstituted 2 to 10 membered heteroalkyl. R⁶may be substituted or unsubstituted 2 to 6 membered heteroalkyl. R⁶ maybe substituted 2 to 6 membered heteroalkyl. R⁶ may be unsubstituted 2 to6 membered heteroalkyl. R⁶ may be substituted or unsubstituted 2 to 5membered heteroalkyl. R⁶ may be substituted 2 to 5 membered heteroalkyl.R⁶ may be unsubstituted 2 to 5 membered heteroalkyl.

R⁶ may be R⁶⁰-substituted or unsubstituted 2 to 20 membered heteroalkyl.R⁶ may be R⁶⁰-substituted 2 to 20 membered heteroalkyl. R⁶ may beR⁶⁰-substituted or unsubstituted 2 to 10 membered heteroalkyl. R⁶ may beR⁶⁰-substituted 2 to 10 membered heteroalkyl. R⁶ may be R⁶⁰-substitutedor unsubstituted 2 to 6 membered heteroalkyl. R⁶ may be R⁶⁰-substituted2 to 6 membered heteroalkyl. R⁶ may be R⁶⁰-substituted or unsubstituted2 to 5 membered heteroalkyl. R⁶ may be R⁶⁰-substituted 2 to 5 memberedheteroalkyl.

R⁶ may be substituted or unsubstituted 3 to 10 membered cycloalkyl. R⁶may be substituted 3 to 10 membered cycloalkyl. R⁶ may be unsubstituted3 to 10 membered cycloalkyl. R⁶ may be substituted or unsubstituted 3 to6 membered cycloalkyl. R⁶ may be substituted 3 to 6 membered cycloalkyl.R⁶ may be unsubstituted 3 to 6 membered cycloalkyl. R⁶ may besubstituted or unsubstituted 3 to 5 membered cycloalkyl. R⁶ may besubstituted 3 to 5 membered cycloalkyl. R⁶ may be unsubstituted 3 to 5membered cycloalkyl. R⁶ may be substituted or unsubstituted 3 memberedcycloalkyl. R⁶ may be substituted 3 membered cycloalkyl. R⁶ may beunsubstituted 3 membered cycloalkyl. R⁶ may be substituted orunsubstituted 4 membered cycloalkyl. R⁶ may be substituted 4 memberedcycloalkyl. R⁶ may be unsubstituted 4 membered cycloalkyl. R⁶ may besubstituted or unsubstituted 5 membered cycloalkyl. R⁶ may besubstituted 5 membered cycloalkyl. R⁶ may be unsubstituted 5 memberedcycloalkyl. R⁶ may be substituted or unsubstituted 6 memberedcycloalkyl. R⁶ may be substituted 6 membered cycloalkyl. R⁶ may beunsubstituted 6 membered cycloalkyl.

R⁶ may be R⁶⁰-substituted or unsubstituted 3 to 10 membered cycloalkyl.R⁶ may be R⁶⁰-substituted 3 to 10 membered cycloalkyl. R⁶ may beR⁶⁰-substituted or unsubstituted 3 to 6 membered cycloalkyl. R⁶ may beR⁶⁰-substituted 3 to 6 membered cycloalkyl. R⁶ may be R⁶⁰-substituted orunsubstituted 3 to 5 membered cycloalkyl. R⁶ may be R⁶⁰-substituted 3 to5 membered cycloalkyl. R⁶ may be R⁶⁰-substituted or unsubstituted 3membered cycloalkyl. R⁶ may be R⁶⁰-substituted 3 membered cycloalkyl. R⁶may be R⁶⁰-substituted or unsubstituted 4 membered cycloalkyl. R⁶ may beR⁶⁰-substituted 4 membered cycloalkyl. R⁶ may be R⁶⁰-substituted orunsubstituted 5 membered cycloalkyl. R⁶ may be R⁶⁰-substituted 5membered cycloalkyl. R⁶ may be R⁶⁰-substituted or unsubstituted 6membered cycloalkyl. R⁶ may be R⁶⁰ substituted 6 membered cycloalkyl.

R⁶ may be substituted or unsubstituted 3 to 10 memberedheterocycloalkyl. R⁶ may be substituted 3 to 10 memberedheterocycloalkyl. R⁶ may be unsubstituted 3 to 10 memberedheterocycloalkyl. R⁶ may be substituted or unsubstituted 3 to 6 memberedheterocycloalkyl. R⁶ may be substituted 3 to 6 memberedheterocycloalkyl. R⁶ may be unsubstituted 3 to 6 memberedheterocycloalkyl. R⁶ may be substituted or unsubstituted 3 to 5 memberedheterocycloalkyl. R⁶ may be substituted 3 to 5 memberedheterocycloalkyl. R⁶ may be unsubstituted 3 to 5 memberedheterocycloalkyl. R⁶ may be substituted or unsubstituted 3 memberedheterocycloalkyl. R⁶ may be substituted 3 membered heterocycloalkyl. R⁶may be unsubstituted 3 membered heterocycloalkyl. R⁶ may be substitutedor unsubstituted 4 membered heterocycloalkyl. R⁶ may be substituted 4membered heterocycloalkyl. R⁶ may be unsubstituted 4 memberedheterocycloalkyl. R⁶ may be substituted or unsubstituted 5 memberedheterocycloalkyl. R⁶ may be substituted 5 membered heterocycloalkyl. R⁶may be unsubstituted 5 membered heterocycloalkyl. R⁶ may be substitutedor unsubstituted 6 membered heterocycloalkyl. R⁶ may be substituted 6membered heterocycloalkyl. R⁶ may be unsubstituted 6 memberedheterocycloalkyl.

R⁶ may be R⁶⁰-substituted or unsubstituted 3 to 10 memberedheterocycloalkyl. R⁶ may be R⁶⁰-substituted 3 to 10 memberedheterocycloalkyl. R⁶ may be R⁶⁰-substituted or unsubstituted 3 to 6membered heterocycloalkyl. R⁶ may be R⁶⁰-substituted 3 to 6 memberedheterocycloalkyl. R⁶ may be R⁶⁰-substituted or unsubstituted 3 to 5membered heterocycloalkyl. R⁶ may be R⁶⁰-substituted 3 to 5 memberedheterocycloalkyl. R⁶ may be R⁶⁰-substituted or unsubstituted 3 memberedheterocycloalkyl. R⁶ may be R⁶⁰-substituted 3 membered heterocycloalkyl.R⁶ may be R⁶⁰-substituted or unsubstituted 4 membered heterocycloalkyl.R⁶ may be R⁶⁰-substituted 4 membered heterocycloalkyl. R⁶ may beR⁶⁰-substituted or unsubstituted 5 membered heterocycloalkyl. R⁶ may beR⁶⁰-substituted 5 membered heterocycloalkyl. R⁶ may be R⁶⁰-substitutedor unsubstituted 6 membered heterocycloalkyl. R⁶ may be R⁶⁰-substituted6 membered heterocycloalkyl.

R⁶ may be substituted or unsubstituted aryl. R⁶ may be substituted aryl.R⁶ may be unsubstituted aryl. R⁶ may be substituted or unsubstituted 5to 10 membered aryl. R⁶ may be substituted 5 to 10 membered aryl. R⁶ maybe unsubstituted 5 to 10 membered aryl. R⁶ may be substituted orunsubstituted 5 or 6 membered aryl. R⁶ may be substituted 5 or 6membered aryl. R⁶ may be unsubstituted 5 or 6 membered aryl. R⁶ may besubstituted or unsubstituted 5 membered aryl. R⁶ may be substituted 5membered aryl. R⁶ may be unsubstituted 5 membered aryl. R⁶ may besubstituted or unsubstituted 6 membered aryl. R⁶ may be substituted 6membered aryl. R⁶ may be unsubstituted 6 membered aryl.

R⁶ may be R⁶⁰-substituted or unsubstituted aryl. R⁶ may beR⁶⁰-substituted aryl. R⁶ may be R⁶⁰-substituted or unsubstituted 5 to 10membered aryl. R⁶ may be R⁶⁰-substituted 5 to 10 membered aryl. R⁶ maybe R⁶⁰-substituted or unsubstituted 5 or 6 membered aryl. R⁶ may beR⁶⁰-substituted 5 or 6 membered aryl. R⁶ may be R⁶⁰-substituted orunsubstituted 5 membered aryl. R⁶ may be R⁶⁰-substituted 5 memberedaryl. R⁶ may be R⁶⁰-substituted or unsubstituted 6 membered aryl. R⁶ maybe R⁶⁰-substituted 6 membered aryl.

R⁶ may be substituted or unsubstituted heteroaryl. R⁶ may be substitutedheteroaryl. R⁶ may be unsubstituted heteroaryl. R⁶ may be substituted orunsubstituted 5 to 10 membered heteroaryl. R⁶ may be substituted 5 to 10membered heteroaryl. R⁶ may be unsubstituted 5 to 10 memberedheteroaryl. R⁶ may be substituted or unsubstituted 5 or 6 memberedheteroaryl. R⁶ may be substituted 5 or 6 membered heteroaryl. R⁶ may beunsubstituted 5 or 6 membered heteroaryl. R⁶ may be substituted orunsubstituted 5 membered heteroaryl. R⁶ may be substituted 5 memberedheteroaryl. R⁶ may be unsubstituted 5 membered heteroaryl. R⁶ may besubstituted or unsubstituted 6 membered heteroaryl. R⁶ may besubstituted 6 membered heteroaryl. R⁶ may be unsubstituted 6 memberedheteroaryl.

R⁶ may be R⁶⁰-substituted or unsubstituted heteroaryl. R⁶ may beR⁶⁰-substituted heteroaryl. R⁶ may be R⁶⁰-substituted or unsubstituted 5to 10 membered heteroaryl. R⁶ may be R⁶⁰-substituted 5 to 10 memberedheteroaryl. R⁶ may be R⁶⁰-substituted or unsubstituted 5 or 6 memberedheteroaryl. R⁶ may be R⁶⁰-substituted 5 or 6 membered heteroaryl. R⁶ maybe R⁶⁰-substituted or unsubstituted 5 membered heteroaryl. R⁶ may beR⁶⁰-substituted 5 membered heteroaryl. R⁶ may be R⁶⁰-substituted orunsubstituted 6 membered heteroaryl. R⁶ may be R⁶⁰-substituted 6membered heteroaryl.

R⁶⁰ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R⁶¹-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R⁶¹-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R⁶¹-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R⁶¹-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R⁶¹-substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or R⁶¹-substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl. R⁶⁰ may be hydrogen, halogen, oxo, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, substituted orunsubstituted (e.g. C₁-C₅) alkyl, substituted or unsubstituted (e.g. 2to 5 membered) heteroalkyl, substituted or unsubstituted (e.g. C₃-C₈)cycloalkyl, substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, substituted or unsubstituted aryl (e.g. phenyl ornaphthyl), or substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl. R⁶⁰ may be hydrogen, halogen, oxo, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g.C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5 membered) heteroalkyl,unsubstituted (e.g. C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8membered) heterocycloalkyl, unsubstituted aryl (e.g. phenyl ornaphthyl), or unsubstituted (e.g. 5 or 6 membered or fused ring)heteroaryl.

R⁶¹ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R⁶²-substituted or unsubstituted alkyl,R⁶²-substituted or unsubstituted heteroalkyl, R⁶²-substituted orunsubstituted cycloalkyl, R⁶²-substituted or unsubstitutedheterocycloalkyl, R⁶²-substituted or unsubstituted aryl, orR⁶²-substituted or unsubstituted heteroaryl.

R⁶² is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, R⁶³-substituted or unsubstituted (e.g.C₁-C₅) alkyl, R⁶³-substituted or unsubstituted (e.g. 2 to 5 membered)heteroalkyl, R⁶³-substituted or unsubstituted (e.g. C₃-C₈) cycloalkyl,R⁶³-substituted or unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, R⁶³-substituted or unsubstituted e.g. phenyl ornaphthyl), or R⁶³-substituted or unsubstituted (e.g. 5 or 6 membered orfused ring) heteroaryl.

R⁶³ is hydrogen, halogen, oxo, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, unsubstituted (e.g. C₁-C₅) alkyl,unsubstituted (e.g. 2 to 5 membered) heteroalkyl, unsubstituted (e.g.C₃-C₈) cycloalkyl, unsubstituted (e.g. 3 to 8 membered)heterocycloalkyl, unsubstituted aryl (e.g. phenyl or naphthyl), orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

R^(6A) and R^(6B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, or —ONH₂. R^(6A) andR^(6B) may independently be substituted or unsubstituted alkyl,substituted or unsubstituted heteroalkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heterocycloalkyl, substitutedor unsubstituted aryl, or substituted or unsubstituted heteroaryl.R^(6A) and R^(6B) may independently be hydrogen, oxo, halogen, —CF₃,—CN, —OH, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₃H, —ONH₂, —NHC(O)NHNH₂,R⁶⁰-substituted or unsubstituted (e.g. C1-C₅) alkyl, R⁶⁰-substituted orunsubstituted (e.g. 2 to 5 membered) heteroalkyl, R⁶⁰-substituted orunsubstituted (e.g. C₃-C₈) cycloalkyl, R⁶⁰-substituted or unsubstituted(e.g. 3 to 8 membered) heterocycloalkyl, R⁶⁰-substituted orunsubstituted aryl (e.g. phenyl or naphthyl), or R⁶⁰-substituted orunsubstituted (e.g. 5 or 6 membered or fused ring) heteroaryl.

R^(6A) and R^(6B) may independently be R^(6C)-substituted orunsubstituted (e.g. C₁-C₅) alkyl, R^(6C)-substituted or unsubstituted(e.g. 2 to 5 membered) heteroalkyl, R^(6C)-substituted or unsubstituted(e.g. C₃-C₈) cycloalkyl, R^(6C)-substituted or unsubstituted (e.g. 3 to8 membered) heterocycloalkyl, R^(6C)-substituted or unsubstituted aryl(e.g. phenyl or naphthyl), or R^(6C)-substituted or unsubstituted (e.g.5 or 6 membered or fused ring) heteroaryl.

R^(6C) is hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂, —ONH₂,—NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH, —OCF₃,—OCHF₂, unsubstituted (e.g. C₁-C₅) alkyl, unsubstituted (e.g. 2 to 5membered) heteroalkyl, unsubstituted (e.g. C₃-C₈) cycloalkyl,unsubstituted (e.g. 3 to 8 membered) heterocycloalkyl, unsubstitutedaryl (e.g. phenyl or naphthyl), or unsubstituted (e.g. 5 or 6 memberedor fused ring) heteroaryl.

The compound of formula (I) may have the formula:

L¹, R¹, R², X, Y, and m1 are as described herein. R² of the compounds offormula (II) or (III) may be halogen or —OR^(2A), where R^(2A) ishydrogen or unsubstituted C₁-C₅ alkyl compounds. X of formula (II) or(III) may be —CH₂— or —N—. Y of formula (II) or (III) may be —NH— or—O—. L¹ of formula (II) or (III) may be a bond. R¹ of formula (II) or(III) may be halogen, —NO₂, —NH₂, —OR^(1A), where R^(1A) is hydrogen orunsubstituted C₁-C₅ alkyl, where the symbol m1 is 1, 2, or 3.

The compound of formula (I) may have the formula:

where R¹, m1, R², and X are as described herein. R¹ may be —OR^(1A),where R^(1A) is as described herein (e.g. substituted or unsubstitutedalkyl) and m1 is 1, 2, or 3. R¹ may be halogen. R¹ may be —CF₃. R¹ maybe —NO₂. R¹ may be —NH₂. R¹ may be substituted at the 2, 3, or 4positions with one or more of be —OR^(1A), where R^(1A) is as describedherein (e.g. substituted or unsubstituted alkyl), halogen, —CF₃, —NO₂,or —NH₂. The symbol m1 may be 1, 2, or 3.

The compound of formula (I) may have the formula:

where L¹, R¹, m1, R² and X are as described herein. L¹ may be a bond andR¹ may be —OR^(1A), where R^(1A) is as defined herein (e.g. substitutedor unsubstituted alkyl) and m1 is 1, 2, or 3. R¹ may be halogen. R¹ maybe —CF₃. R¹ may be —NO₂. R¹ may be —NH₂. R¹ may be substituted at the 2,3, or 4 positions with one or more of be —OR^(1A), where R^(1A) is asdescribed herein (e.g. substituted or unsubstituted alkyl), halogen,—CF₃, —NO₂, or —NH₂. The symbol m1 may be 1, 2, or 3.

The compound of formula (I) may have formula:

where A is 5,6-fused ring heteroaryl, 6,5-fused ring heteroaryl, or6,6-fused ring heteroaryl. L¹, R¹, m1, R², X and Y are as describedherein. R² of the compounds of formula (IV) or formula (V) may behalogen or —OR^(2A), where R^(2A) is hydrogen or unsubstituted C₁-C₅alkyl. X of the compounds of formula (IV) or formula (V) may be —CH₂— or—N—. Y of the compounds of formula (IV) or formula (V) may be —NH— or—O—. L¹ of the compounds of formula (IV) or formula (V) may be a bond.R¹ of the compounds of formula (IV) or formula (V) may be halogen, —NO₂,—NH₂, —OR^(1A), where R^(1A) is hydrogen or unsubstituted C₁-C₅ alkylwhere the symbol m1 is 1, 2, or 3.

The compound of formula (I) may be a compound having the structure setforth in Table 1, 2, or 3, or in the examples provided herein.

TABLE 1 Compounds and inhibition of HDAC8 (relative potency) and HeLanuclear HDACs (IC₅₀, nM)

IC₅₀ Com- PCI34051/IC₅₀ HeLa pound R compound HDAC 5a

0.29 >10000 5b

1.43 >10000 5c

1.17 >10000 5d

1.90 >10000 5e

1.86  8550 ± 0.12 5f

0.64 >10000 5g

0.28 798.4 ± 0.3  5h

0.63 836.0 ± 9.1  PCI34051 1 >10000 X1

X2

X3

X4

X5

TABLE 2 Compounds and inhibition of HDAC8 (relative potency) and HeLanuclear HDACs (IC₅₀, nM) and cytotoxicity (IC₅₀, μM)

IC₅₀ PCI34051/IC₅₀ HeLa Compound R compound HDAC 6a H 0.40 >10000 6b2-OMe 0.17 >10000 6c 3-OMe 0.44 >10000 6d 4-OMe 0.30 >10000 6e 3,4-diOMe0.44 >10000 6f 3,4,5-triOMe 0.24 >10000 PCI34051 1 >10000 X6 2- or 3- or4-R (R = F, Cl, Br) X7 2- or 3- or 4-R (R = NO₂) X8 2- or 3- or 4-R (R =NH₂) X9 2- or 3- or 4-CF₃

TABLE 3 Compounds and inhibition of HDAC 8 (relative potency) and HeLanuclear HDACs (IC₅₀, nM)

IC₅₀ PCI34051/IC₅₀ HeLa Compound R compound HDAC 15a 4-F 0.38 >10000 15b4- CF₃ 0.55 >10000 15c 5-OMe 0.06 >10000 15d 3,4-OMe 0.44 >10000 15e3,4,5-OMe 0.02 >10000 21 0.68 >10000 25 0.49 >10000 PCI-34051 1 X10 3-or 5- or 6-R, (R = F) X11 3- or 4-or 5- or 6-R (R = Cl, Br) X12 3- or4-or 5- or 6-R (R = NO₂) X13 3- or 4-or 5- or 6-R (R = NH₂) X14 3- or4-or 5- or 6-R CF₃

In embodiments, R¹ and R² of the compound of formula (I) are notunsubstituted aryl. In embodiments R¹ and R² of the compound of formula(I) are not unsubstituted phenyl. In embodiments, when L¹ is a bond, R¹is not unsubstituted aryl or unsubstituted heteroaryl. In embodiments,when L¹ is a bond, R¹ is not substituted or unsubstituted aryl (e.g.phenyl). In embodiments, when L¹ is a bond, R¹ is not —OR^(1A), whereR^(1A) is methyl or substituted or unsubstituted benzyl. In embodiments,when L¹ is a bond, R¹ is not —OR^(1A), where R^(1A) is methyl orsubstituted or unsubstituted benzyl and R² is not —OCH₃. In embodiments,when L¹ is substituted or unsubstituted arylene, R¹ is not substitutedor unsubstituted aryl. In embodiments, when L¹ is unsubstituted arylene(e.g. phenyl), R¹ is not substituted or unsubstituted aryl. Inembodiments when L¹ is unsubstituted arylene, R¹ is not unsubstitutedaryl (e.g. phenyl). In embodiments the compound is not a compound as setforth in Scheme 1. In embodiments the compound is not a compound as setforth in Scheme 2. In embodiments the compound is not a compound as setforth in Scheme 3. In embodiments the compound is not a compound as setforth in Scheme 4. In embodiments the compound is not a compound as setforth in Scheme 5. In embodiments the compound is not a compound as setforth in Scheme 6. In embodiments the compound is not a compound as setforth in Table 1. In embodiments the compound is not a compound as setforth in Table 4. In embodiments the compound is not a compound as setforth in Table 5. In embodiments the compound is not a compound as setforth in Table 6.

In embodiments, the compound is not a compound having formula:

-   -   where R′═H, 4-Cl, 4-Br, 4-OCH₃, 3,4-C₆H4, 4-OCF₃.

In embodiments, the compound is not a compound having formula:

-   -   where R″═H, 4-Cl, 4-Br, 4-OCH₃, 3,4-C₆H4.

In embodiments, the compound is not a compound having formula:

-   -   where n is 2-5.

In embodiments, the compound is not a compound having formula:

-   -   where R′″ is:

In embodiments, the compound is not a compound having formula:

II. METHODS OF TREATING

Provided herein are methods of treating cancer with a HDAC8 inhibitor.In one aspect, the method is a method of treating cancer byadministering to a subject in need thereof an effective amount of aHDAC8 inhibitor as described herein. The HDAC8 inhibitor is as describedherein. The HDAC8 inhibitor may be a compound of formula (I) asdescribed herein including one or more compounds set forth in Tables 1-3and/or one or more of those set forth in the Examples. The HDAC8inhibitor may be an HDAC8 inhibitor antibody. The HDAC8 inhibitor may bea HDAC8 inhibitor polynucleotide. The HDAC8 inhibitor may be a HDAC8inhibitor protein. The inhibitor may block the active site of HDAC8.

The cancer may be a non-mutated p53 cancer. The non-mutated p53 cancermay be a blood cancer (e.g. a non-mutated p53 blood cancer) or a solidtumor cancer (e.g. a non-mutated p53 solid tumor cancer). Thenon-mutated p53 cancer may be acute myeloid leukemia (AML), acutelymphoblastic leukemia (ALL), lymphoma, neuroblastoma, glioma, bladdercancer, lung cancer, non-small cell lung cancer, or breast cancer(including triple-negative breast cancer).

The non-mutated p53 cancer may be acute myeloid leukemia (AML), acutelymphoblastic leukemia (ALL), lymphoma, neuroblastoma, glioma, bladdercancer, or lung cancer. The non-mutated p53 cancer may be acute myeloidleukemia (AML), acute lymphoblastic leukemia (ALL), lymphoma,neuroblastoma, or glioma. The non-mutated p53 cancer may be acutemyeloid leukemia (AML), acute lymphoblastic leukemia (ALL), or lymphoma.The non-mutated p53 cancer may be acute myeloid leukemia (AML) or acutelymphoblastic leukemia (ALL).

The non-mutated p53 cancer may be acute myeloid leukemia (AML). Thenon-mutated p53 cancer may be acute lymphoblastic leukemia (ALL). Thenon-mutated p53 cancer may be lymphoma. The non-mutated p53 cancer maybe neuroblastoma. The non-mutated p53 cancer may be glioma. Thenon-mutated p53 cancer may be bladder cancer. The non-mutated p53 cancermay be lung cancer. The non-mutated p53 cancer may be non-small celllung cancer. The non-mutated p53 cancer may be breast cancer (includingtriple-negative breast cancer).

The cancer may have increased HDAC8 activity or expression when comparedto a non-cancerous cell. The cancer may have increased HDAC8 activityand expression when compared to a non-cancerous cell. The cancer mayhave increased HDAC8 activity when compared to a non-cancerous cell. Thecancer may have increased HDAC8 expression when compared to anon-cancerous cell.

The non-mutated p53 cancer may have increased HDAC8 activity orexpression when compared to a mutated p53 cancer. The non-mutated p53cancer may have increased HDAC8 activity and expression when compared toa mutated p53 cancer. The non-mutated p53 cancer may have increasedHDAC8 activity when compared to a mutated p53 cancer. The non-mutatedp53 cancer may have increased HDAC8 expression when compared to amutated p53 cancer. p53 may be deacetylated in the non-mutated cancer.p53 may be deacetylated in a non-mutated cancer having increased HDAC8activity or expression. The non-mutated p53 cancer may have deacetylatedp53 and may be characterized by increased resistance to treatment withan anti-cancer agent when compared to a cancer having mutated p53. Thenon-mutated p53 cancer may have increased HDAC8 expression and may becharacterized by increased resistance to treatment with an anti-canceragent when compared to a cancer having mutated p53.

The methods described herein may further include determining whether thenon-mutated cancer has increased HDAC8 activity or HDAC8 expression.Increased HDAC8 activity or HDAC8 expression may be determined usingtechniques known in the art. Thus the level of HDAC8 activity may bemeasured from a sample taken from the subject and compared to the levelof HDAC8 activity in a control sample (e.g. a healthy or non-cancerouscell). The level of HDAC8 expression may be determined using methods ofquantifying a polypeptide (e.g. fluorometric or colorimetric assays,IHC, ELISA, or western blots). The level of HDAC8 expression may bedetermined using methods of quantifying a polynucleotide (e.g.fluorometric or colorimetric assays, PCR, or northern blots).

Also provided herein are methods of determining whether a subject has anon-mutated p53 cancer. Determining the presence or absence ofnon-mutated p53 in a cancer may allow for more effective treatment inthe subject. The method may further include determining the expressionor activity levels of HDAC8 in the non-mutated p53 cancer. When anon-mutated p53 cancer in the subject is determined to also haveincreased activity or expression of HDAC8, the cancer may be resistantto anti-cancer agents. When the non-mutated cancer in the subject isdetermined to also have increased activity or expression of HDAC8, p53in the non-mutated cancer may be deacetylated.

The non-mutated p53 cancer may be leukemia where the cancer also hasincreased HDAC expression or activity. The non-mutated p53 cancer may beleukemia where the cancer also has increased HDAC expression. Thenon-mutated p53 cancer may be leukemia where the cancer also hasincreased HDAC activity.

In another aspect, the method is a method of treating cancer stem cellsby administering to a subject in need thereof an effective amount of aHDAC8 inhibitor as described herein. The HDAC inhibitor is as describedherein. The HDAC8 inhibitor may inhibit the leukemia-initiating capacity(e.g. population of cancer stem cells causing relapse). The cancer stemcells may be resistant to treatment with anti-cancer agents listedherein. Thus, treatments with an HDAC8 inhibitor described herein maytarget cancer stem cells resistant to such treatments and allow efficacyof previously resistant anti-cancer agents.

The HDAC8 inhibitor may be selective for HDAC8 over other HDAC isoforms(e.g. HDAC1, HDAC2, HDAC3, HDAC6, HDAC10, or HDAC 11). The HDAC8inhibitor may be at least 1, 2, 5, 10, 15, 25, 50, 100, 200, 300, 400,or 500× more selective (e.g. by determining K_(i) or IC₅₀ values for thecompound for HDAC8 and other HDAC isoforms described herein).

Also provided herein are methods of treating cancer by modulating p53activity. In one aspect, is a method of treating cancer by modulatingp53 activity by administering to a subject in need thereof a HDAC8inhibitor as described herein. The HDAC8 inhibitor may be a compounddescribed herein. The cancer is as described herein. The cancer mayoverexpress HDAC8.

III. METHODS OF INHIBITING

Further provided herein are methods of inhibiting HDAC8 mediateddeacetylation of p53. In one aspect, the method includes contactingHDAC8 with a HDAC8 inhibitor as described herein, thereby inhibitingHDAC8 mediated deacetylation of p53. The inhibition of HDAC8 may allowfor acetylation and activation of p53, thereby mediating cell apoptosis.

The contacting may be performed in vitro or in vivo. The contacting maybe performed in vitro. The contacting may be performed in vivo. Thecontacting may be performed in an organism.

The inhibition of HDAC8 mediated deacetylation of p53 may be monitoredby techniques known in the art, including for example, fluorescent andcolorimetric assays.

IV. METHODS OF ACTIVATING

Further provided herein are methods of activating p53. The method may bea method of activating p53 in vivo by contacting a cell with a HDAC8inhibitor in the presence of HDAC8 and allowing the HDAC8 inhibitor tocontact the HDAC8, thereby inhibiting the HDAC8 and activating p53. Thecontacting is performed as described herein. The HDAC8 inhibitor is asdescribed herein. The HDAC8 inhibitor may be a compound describedherein.

V. EXAMPLES Example 1. Chemical Design

The synthesis of N-hydroxycinnamides 8a-f is illustrated in Scheme 1following. 7-Hydroxycoumarin 3 reacted with the appropriate benzylbromides gave corresponding coumarins 4a-f. Ethanolysis of compounds4a-f using sodium ethoxide under anhydrous conditions provided (E)-ethylcinnamates 5a-f,[26] respectively. Methylation of compounds 5a-f reactedwith DMS gave corresponding cinnamic esters 6a-f. Saponification ofcompounds 6a-f in the presence of LiOH gave corresponding cinnamic acids7a-f in quantitative yields. Compounds 7a-f reacted with ethylchlorformate to produce the corresponding activated mixed anhydride insitu, and subsequent treatment of the prepared hydroxylamine gaveN-hydroxycinnamides 8a-f, respectively. The synthesis ofN-hydroxycinnamides 13a-e is described in Scheme 2. Ethanolysis of7-methoxycoumarin 9 gave (E)-ethyl cinnamate 10. Reaction of (E)-ethylcinnamate 10 with the appropriate benzyl bromides provided cinnamicesters 11 a-e, respectively. N-Hydroxycinnamides 13a-e were achievedstarting from compounds 11 a-e through saponification followed byreaction with ethyl chloroformate and hydroxylamine according to thesynthetic approach for 8a-f. The synthesis of N-hydroxycinnamides 18a-dis shown in Scheme 3.

Reaction of 4-methoxyphenol 14 with the appropriate chlorosubstitutedalkyl bromides with chain lengths of two to five carbons yieldedcorresponding compounds 15a-d. Coupling of ethyl cinnamate 10 with 15a-dgave compounds 16a-d, respectively. Saponification of compounds 16a-dand subsequent reaction with ethyl chloroformate and hydroxylamine gavecorresponding N-hydroxycinnamides 18a-d. The synthesis of ortho-arylN-hydroxycinnamides 22a-g is described in Scheme 4. Reaction of ethylcinnamate 10 with trifluoromethanesulfonyl (triflic) anhydride in thepresence of pyridine gave compound 19. Suzuki coupling[27] of 19 withthe appropriate aryl borates using catalytictetrakis(triphenylphosphine) palladium yielded compounds 20a-g,respectively. Using compound 20a-g as the starting material,saponification followed by reaction with ethyl chloroformate andhydroxylamine gave corresponding the N-hydroxycinnamides 22a-g. Thesynthesis of ortho-phenyl N-hydroxycinnamides 27a-c with various chainlengths at the para position is achieved as described in Scheme 5.Reaction of 7-hydroxycoumarin 3 with the appropriate alkyl bromides witha three- to five-carbon chain length gave 23a-c, respectively.Ethanolysis of compounds 23a-c yielded corresponding (E)-ethylcinnamates 24a-c. Reaction of compounds 24a-c with triflic anhydrideprovided 25a-c, respectively. Suzuki coupling of compounds 25a-c withphenyl borate gave corresponding compounds 26a-c. Ethyl cinnamates 26a-cwas reacted directly with hydroxylamine in the presence of NaOH to yieldN-hydroxycinnamides 27a-c, respectively. The synthesis ofN-hydroxycinnamide 27d with a phenyl group at the ortho and paraposition was achieved as illustrated in Scheme 6. Reaction of7-hydroxycoumarin 3 with triflic anhydride gave 28. Suzuki coupling ofcompound 28 with phenyl borate yielded phenyl coumarin 29. Methanolysisof compound 29 provided (E)-methyl cinnamate 30.Trifluoromethanesulfonylation of compound 30 and subsequent Suzukicoupling was repeated to give 32. Compound 32 was converted intoN-hydroxycinnamide 27d using hydroxylamine and NaOH. Details on thesynthesis, isolation, and characterization of reaction intermediates canbe found in the Supporting Information.

Example 2. Compound Synthesis

General.

¹H NMR spectrum was obtained on a Bruker AV400 or AV500 spectrometerusing standard pulse programs. Melting point was recorded on aFisher-Johns apparatus (uncorrected). MS data were measured on a JEOLJMX-HX110 mass spectrometer (HREIMS and HRFABMS), a JMS-SX102A massspectrometer (EIMS and FABMS), or a Finnigan Mat 95S mass spectrometer(HRESIMS and ESIMS). TLC analyses were carried out on silica gel plates(KG60-F254, Merck). The microplate spectrophotometer Victor 2X(PerkinElmer, Fremont, Calif., USA) was used for fluorometric analysis.Unless otherwise mentioned, all chemicals and materials were used asreceived from commercial suppliers without further purification. CH₂Cl₂was distilled from CaH under N₂. THF was distilled from sodium andbenzophenone under N₂. All test compounds were estimated to be at least98% pure as judged by HPLC analysis, which was performed on an AscentisC18 column (150×4.6 mm) using an L-2130 pump (Hitachi) and a UV/VisL-2420 detector (Hitachi) with UV detection at 250 nm.

7-Benzyloxycoumarin (4a)

To a solution of 7-hydroxy-2H-chromen-2-one (4.86 g, 30.00 mmol) andK₂CO₃ (10.35 g, 75.00 mmol) in acetone (200 mL) was added benzylchloride (6.90 mL, 60.00 mmol). The resulting was heated to 56 C underN₂ overnight. After filtration to remove K₂CO₃, the filtrate wasconcentrated in vacuo. The residue was diluted with distd H₂O (100 mL)and then extracted with EtOAc (50 mL×3). The organic layer was dried(Na₂SO₄), filtered and the solvent removed in vacuo. The residue waspurified by silica gel chromatography (EtOAc: n-Hexane=1:4) to give 4a(6.43 g, 85%) as a white solid: mp: 135-140° C.; ¹H NMR (500 MHz,CDCl₃): δ=7.62 (d, J=9.5 Hz, 1H), 7.42 (m, 3H), 7.37 (d, J=8.7 Hz, 1H),7.34 (m, 2H), 6.91 (d, J=8.7 Hz, 1H), 6.89 (s, 1H), 6.25 (d, J=9.5 Hz,1H), 5.13 ppm (s, 2H); MS (EI, 70 ev) m/z: 252 [M]₊.

7-(4-Chlorobenzyloxy)coumarin (4b)

To a solution of 7-hydroxy-2H-chromen-2-one (5.16 g, 31.85 mmol) andK₂CO₃ (10.99 g, 79.63 mmol) in acetone (200 mL) was added 4-chlorobenzylchloride (10.29 g, 63.70 mmol). Following the procedure as described for4a gave 4b (7.47 g, 82%) as a white solid: mp: 120-125° C.; ¹H NMR (500MHz, CDCl₃): δ=7.63 (d, J=9.5 Hz, 1H), 7.37 (m, 5H), 6.90 (dd, J=2.4,8.6 Hz, 1H), 6.86 (d, J=2.4 Hz, 1H), 6.26 (d, J=9.5 Hz, 1H), 5.09 ppm(s, 2H); MS (EI, 70 ev) m/z: 286 [M]₊.

7-[(Naphthalen-4-yl)methoxyl]coumarin (4e)

To a solution of 7-hydroxy-2H-chromen-2-one (4.45 g, 27.47 mmol) andK₂CO₃ (9.48 g, 68.67 mmol) in acetone (220 mL) was added1-(chloromethyl)naphthalene (8.30 mL, 54.94 mmol). Following theprocedure as described for 4a gave 4e (6.22 g, 75%) as a white solid:mp: 135-150° C.; ¹H NMR (500 MHz, CDCl₃): δ=8.03 (d, J=8.1 Hz, 1H), 7.91(d, J=7.8 Hz, 1H), 7.88 (d, J=8.1 Hz, 1H), 7.63 (d, J=9.5 Hz, 1H), 7.60(m, 1H), 7.56 (m, 2H), 7.48 (t, J=7.8 Hz, 1H), 7.39 (d, J=8.6 Hz, 1H),7.00 (d, J2.2 Hz, 1H), 6.96 (dd, J2.2, 8.6 Hz, 1H), 6.26 (d, J=9.5 Hz,1H), 5.56 ppm (s, 2H); MS (EI, 70 ev) m/z: 302 [M]₊.

(E)-Ethyl 4-benzyloxy-2-hydroxycinnamate (5a)

To a solution of 4a (5.54 g, 22.00 mmol) in anhydrous EtOH (50 mL) wasadded NaOEt (3.12 g, 44.00 mmol) in anhydrous EtOH (50 mL) dropwiseduring 1 h. The resulting solution was heated to 78° C. under N₂ at for6 h. The reaction was diluted with distd H₂O (200 mL), acidified with INHCl(aq) to pH 4-5 and extracted with EtOAc (100 mL×3). The organic layerwas dried (Na₂SO₄), filtered and the solvent removed in vacuo. Theresidue was purified by silica gel chromatography (EtOAc:n-Hexane=1:4)to give 5a (4.92 g, 75%) as a white solid: mp: 120-130° C.; ¹H NMR (500MHz, [D6] DMSO): δ 10.33 (s, 1H), 7.77 (d, J=16.2 Hz, 1H), 7.52 (d,J=9.3 Hz, 1H), 7.40 (m, 5H), 7.33 (d, J=9.3 Hz, 1H), 6.51 (s, 1H), 6.44(d, J=16.2 Hz, 1H), 5.08 (s, 2H), 4.14 (q, J=7.1 Hz, 2H), 1.22 ppm (t,J7.2 Hz, 3H); MS (EI, 70 ev) m/z: 298 [M]+.

(E)-Ethyl 4-(4-chlorobenzyloxy)-2-hydroxycinnamate (5b)

To a solution of 4b (6.26 g, 21.89 mmol) in anhydrous EtOH (60 mL) wasadded NaOEt (3.10 g, 43.78 mmol) in anhydrous EtOH (50 mL) dropwiseduring 1 h. Following the procedure as described for 5a gave 5b (5.23 g,72%) as a white solid: mp: 133-140° C.; ¹H NMR (500 MHz, CDCl₃): δ 7.95(d, J=16.2 Hz, 1H), 7.39 (d, J=8.7 Hz, 1H), 7.35 (dd, J=2.3, 9.0 Hz,4H), 6.66 (s, 1H), 6.53 (dd, J=2.3, 8.7 Hz, 1H), 6.52 (d, J=16.2 Hz,1H), 6.44 (d, J=2.3 Hz, 1H), 5.01 (s, 2H), 4.27 (q, J7.1 Hz, 2H), 1.34ppm (t, J7.1 Hz, 3H); MS (EI, 70 ev) m/z: 332 [M]+.

(E)-Ethyl 2-hydroxy-4-[(naphthalen-4-yl)methoxy]cinnamate (5e)

To a solution of 4e (6.00 g, 19.87 mmol) in anhydrous EtOH (60 mL) wasadded NaOEt (2.81 g, 39.74 mmol) in anhydrous EtOH (50 mL) dropwiseduring 1 h. Following the procedure as described for 5a gave 5e (5.12 g,74%) as a white solid: mp: 139-144° C.; ¹H NMR (500 MHz, [D6]DMSO):δ=10.34 (s, 1H), 8.05 (d, J=8.0 Hz, 1H), 7.97 (d, J=7.6 Hz, 1H), 7.93(d, J=8.7 Hz, 1H), 7.79 (d, J=16.1 Hz, 1H), 7.64 (t, J=6.9 Hz, 1H), 7.57(m, 3H), 7.51 (t, J=7.6 Hz, 1H), 6.61 (dd, =2.1, 8.7 Hz, 1H), 6.57 (d,J=2.1 Hz, 1H), 6.46 (d, J=16.1 Hz, 1H), 5.53 (s, 2H), 4.14 (q, J=7.1 Hz,2H), 1.23 ppm (t. J=7.1 Hz, 3H); MS (EI, 70 ev) m/z: 348 [M]+.

(E)-N-Hydroxy-4-benzyloxy-2-methxycinnamide (8a)

KOH (1.23 g, 22.00 mmol) was added to a solution of NH₂OH (1.53 g, 22.00mmol) in MeOH (20 mL). The resulting solution was stirred in an ice bathfor 1 h. Filtration to remove the white salt gave a solution of NH₂OH inMeOH. A solution of 7a (3.12 g, 11.00 mmol) in freshly distilled THF (30mL) was treated with ethyl chloroformate (1.58 mL, 16.50 mmol) and Et₃N(3.06 mL, 22.00 mmol) and was stirred at room temperature for 1 h. Theprepared free NH₂OH solution was then added to the reaction, andstirring was continued for 3 h. The reaction was diluted with distilledwater (100 mL), acidified with 1n HCl(aq) to pH 2-3, and extracted withEtOAc (3×50 mL). The organic layer was dried (Na₂SO₄) and filtered, andthe solvent was removed in vacuo. The residue was purified by silica gelchromatography (EtOAc/n-hexane, 1:2-1:1) to give 8a (1.81 g, 55%) as awhite solid: mp: 128-135° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.60 (s,1H), 8.89 (s, 1H), 7.58 (d, J=15.9 Hz, 1H), 7.45 (t, J=7.4 Hz, 2H), 7.42(d, J=8.5 Hz, 1H), 7.38 (t, J=7.4 Hz, 2H), 7.33 (d, J=7.4 Hz, 1H), 6.70(d, J=1.9 Hz, 1H), 6.64 (dd, J=1.9, 8.5 Hz, 1H), 6.37 (d, J=15.9 Hz,1H), 5.14 (s, 2H), 3.83 ppm (s, 3H); ¹³C NMR (125 MHZ, [D6]DMSO):d=161.6, 160.0, 137.2, 134.9, 129.6, 128.4, 127.9, 127.7, 116.9, 106.6,99.2, 69.8, 55.2 ppm; HRMS-EI: m/z [M]+ calcd for C₁₇H₁₇NO₄: 299.1157,found: 299.1160.

(E)-N-Hydroxy-4-(4-chlorobenzyloxy)-2-methoxycinnamide (8b)

Following the procedure as described for 8a, reaction of 7b (3.50 g,11.00 mmol) in THF (40 mL) with ethyl chloroformate (1.54 mL, 16.50mmol) and Et₃N (2.31 mL, 16.50 mmol) gave 8b (1.94 g, 53%) as a whitesolid: mp: 167-172° C.; ¹H NMR (500 MHz, [D6]DMSO): d=7.57 (d, J=15.8Hz, 1H), 7.47 (d, J=8.6 Hz, 2H), 7.44 (d, J=8.6 Hz, 2H), 7.42 (d, J=8.8Hz, 1H), 6.68 (s, 1H), 6.62 (d, J=8.8 Hz, 1H), 6.36 (d, J=15.8 Hz, 1H),5.14 (s, 2H), 3.82 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO): d=164.1,161.0, 159.4, 136.3, 133.0, 130.1, 129.7, 128.9, 117.4, 116.9, 107.1,99.9, 69.1, 56.2 ppm; HRMS-ESI: m/z [M⁻H]⁻ calcd for C₁₇H₁₅NO₄Cl:332.0690, found: 332.0693.

(E)-N-Hydroxy-4-(4-bromobenzyloxy)-2-methoxycinnamide (8c)

Following the procedure as described for 8a, reaction of 7c (3.80 g,10.50 mmol) in THF (40 mL) with ethyl chloroformate (1.47 mL, 15.75mmol) and Et₃N (2.21 mL, 15.75 mmol) gave 8c (2.26 g, 57%) as a whitesolid: mp: 165-170° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.60 (s, 1H),8.89 (s, 1H), 7.59 (d, J=8.2 Hz, 2H), 7.56 (d, J=16.0 Hz, 1H), 7.42 (d,J=8.2 Hz, 3H), 6.69 (d, J=2.1 Hz, 1H), 6.63 (dd, J=2.1, 8.6 Hz, 1H),6.37 (d, J=16.0 Hz, 1H), 5.13 (s, 2H), 3.84 ppm (s, 3H); ¹³C NMR (125MHz, [D6]DMSO): d=164.1, 161.0, 159.4, 136.7, 133.7, 131.9, 130.4,129.7, 121.5, 117.4, 116.9, 107.1, 99.9, 69.1, 56.2 ppm; HRMS-EI: m/z[M]+ calcd for C₁₇H₁₆BrNO₄: 377.0263, found: 377.0259.

(E)-N-Hydroxy-4-(4-methoxybenzyloxy)-2-methoxycinnamide (8d)

Following the procedure as described for 8a, reaction of 7d (3.50 g,11.15 mmol) in THF (35 mL) with ethyl chloroformate (1.56 mL, 16.73mmol) and Et₃N (2.35 mL, 16.73 mmol) gave 8d (2.02 g, 55%) as a whitesolid: mp: 140-150° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.60 (s, 1H),8.89 (s, 1 H), 7.58 (d, J=15.9 Hz, 1H), 7.41 (d, J=8.5 Hz, 1H), 7.38 (d,J=8.3 Hz, 2H), 6.94 (d, J=8.3 Hz, 2H), 6.67 (s, 1H), 6.63 (d, J=8.5 Hz,1H), 6.37 (d, J=15.9 Hz, 1H), 5.05 (s, 2H), 3.83 (s, 3H), 3.75 ppm (s,3H); ¹³C NMR (125 MHz, [D6]DMSO): d=164.2, 161.3, 159.6, 159.4, 133.8,130.1, 129.6, 129.1, 117.2, 116.7, 114.3, 107.2, 99.8, 69.7, 56.1, 55.6ppm; HRMS-EI: m/z [M]+ calcd for C₁₈H₁₉NO₅:329.1263, found: 329.1259.

(E)-N-Hydroxy-4-[(naphthalen-4-yl)methoxy]-2-methoxycinnamide (8e)

Following the procedure as described for 8a, reaction of 7e (3.15 g,9.43 mmol) in THF (35 mL) with ethyl chloroformate (1.32 mL, 14.15 mmol)and Et₃N (1.99 mL, 14.15 mmol) gave 8e (1.67 g, 51%) as a white solid:mp: 150-158° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.61 (s, 1H), 8.91 (s,1H), 8.09 (d, J=8.2 Hz, 1H), 7.97 (d, J=7.7 Hz, 1H), 7.94 (d, J=8.2 Hz,1H), 7.69 (d, J=7.7 Hz, 1H), 7.61 (d, J=9.1 Hz, 1H), 7.56 (m, 3H), 7.52(t, J=7.7 Hz, 1H), 7.46 (d, J=15.9 Hz, 1H), 6.78 (s, 1H), 6.75 (d, J=8.6Hz, 1H), 6.39 (d, J=15.9 Hz, 1H), 5.59 (s, 2H), 3.84 ppm (s, 3H); ¹³CNMR (125 MHz, [D6]DMSO): d=164.2, 161.4, 159.4, 133.8, 132.7, 131.6,129.7, 129.3, 129.0, 127.4, 127.0, 126.5, 125.9, 124.4, 117.3, 116.9,107.3, 99.8, 68.5, 56.2 ppm; HRMS-ESI m/z [M⁻H]⁻ calcd for C₂₁H₁₈NO₄Cl:348.1236, found: 348.1235.

(E)-N-Hydroxy-4-(trifluoromethoxy)-2-methoxycinnamide (8f)

Following the procedure as described for 8a, reaction of 7 f (4.50 g,12.23 mmol) in THF (45 mL) with ethyl chloroformate (1.71 mL, 18.35mmol) and Et₃N (2.58 mL, 18.35 mmol) gave 8 f (2.72 g, 58%) as a whitesolid: mp: 155-160° C.; ¹H NMR (500 MHz, [D6]DMSO): d=7.58 (d, J=8.5 Hz,2H), 7.57 (d, J=16.6 Hz, 1H), 7.43 (d, J=8.5 Hz, 1H), 7.38 (d, J=8.5 Hz,2H), 6.69 (d, J=1.9 Hz, 1H), 6.64 (d, J=8.5 Hz, 1H), 6.37 (d, J=16.6 Hz,1H), 5.17 (s, 2H), 3.82 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO):d=161.0, 159.4, 148.4, 136.8, 133.7, 130.1, 129.7, 121.5, 117.4, 117.0,107.1, 99.9, 69.0, 56.2 ppm; HRMS-EI: m/z [M]+ calcd for C₁₁H₁₆F₃NO₅:383.0980, found: 383.0981.

(E)-N-Hydroxy-2-benzyloxy-4-methoxycinnamide (13a)

KOH (1.46 g, 26.00 mmol) to a solution of NH₂OH.HCl (1.81 g, 26.00 mmol)in MeOH (20 mL). The resulting mixture was stirred in an ice bath for 1h. Filtration to remove the white salt gave a solution of NH₂OH in MeOH.A solution of 12a (3.69 g, 13.00 mmol) in freshly distilled THF (45 mL)was treated with ethyl chloroformate (1.29 mL, 20.97 mmol), Et₃N (3.61mL, 26.00 mmol) and the resulting solution was stirred at roomtemperature for 1 h. The prepared free NH₂OH solution was then added tothe reaction and stirring was continued for 3 h. The reaction wasdiluted with distilled water (100 mL), acidified with 1n HCl(aq) to pH2-3, and extracted with EtOAc (3_50 mL). The combined organic layer wasdried (Na₂SO₄) and filtered, and the solvent was removed in vacuo. Theresidue was purified by silica gel chromatography (EtOAc/n-hexane, 1:1)to give 13a (1.55 g, 40%) as a white solid: mp: 134-140° C.; ¹H NMR (500MHz, [D6]acetone): d=8.02 (d, J=15.8 Hz, 1H), 7.62 (d, J=7.5 Hz, 3H)7.52 (t, J=7.2 Hz, 2H), 7.45 (t, J=7.3 Hz, 1H), 6.80 (d, J=2.2 Hz, 1H),6.68 (dd, J=8.6, 2.3 Hz, 1H), 6.66 (d, J=8.6 Hz, 1H), 6.52 (d, J=15.8Hz, 1H), 5.36 (s, 2H), 3.92 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO):d=164.1, 162.1, 158.1, 137.3, 133.5, 129.1, 129.0, 128.4, 128.0, 117.2,117.0, 106.7, 100.4, 70.1, 55.9 ppm; HRMS-FAB: m/z [M+H]+ calcd forC₁₇H₁₈NO₄: 300.1235, found: 300.1234.

(E)-N-Hydroxy-2-(4-chlorobenzyloxy)-4-methoxycinnamide (13b)

Following the procedure as described for 13a, reaction of 12b (2.53 g,7.86 mmol) in THF (40 mL) with ethyl chloroformate (1.10 mL, 11.79 mmol)and Et₃N (1.65 mL, 11.79 mmol) gave 13b (1.10 g, 42%) as a white solid:mp: 160-170° C.; ¹H NMR (500 MHz, [D4]MeOH): d=11.04 (s, 1H), 9.69 (s,1H), 8.44 (d, J=15.9 Hz, 1H), 8.27 (d, J=8.8 Hz, 1H), 8.25 (br s, 4H),7.48 (d, J=1.9 Hz, 1H), 7.39 (dd, J=8.8, 1.9 Hz, 1H), 7.16 (d, J=15.9Hz, 1H), 6.01 (s, 2H), 4.57 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO):d=164.1, 162.0, 157.9, 136.3, 133.5, 133.0, 129.9, 129.3, 129.1, 117.3,117.0, 106.8, 100.4, 69.3, 55.9 ppm; HRMS-ESI: m/z [M+H]+ calcd forC₁₇H₁₇ClNO₄: 334.0846, found: 334.0843.

(E)-N-Hydroxy-2-(4-bromobenzyloxy)-4-methoxycinnamide (13c)

Following the procedure as described for 13a, reaction of 12c (3.50 g,9.67 mmol) in THF (40 mL) with ethyl chloroformate (1.35 mL, 14.51 mmol)and Et₃N (2.03 mL, 14.51 mmol) gave 13c (1.46 g, 40%) as a white solid:mp: 148-155° C.; ¹H NMR (500 MHz, [D6]acetone): d=10.17 (s, 1H), 7.18(d, J=16.1 Hz, 1H), 7.14 (d, J=8.3 Hz, 2H), 7.00 (d, J=8.6 Hz, 1H), 6.96(d, J=8.3 Hz, 2H), 6.21 (s, 1H), 6.13 (d, J=8.6 Hz, 1H), 5.90 (d, J=16.1Hz, 1H), 4.73 (s, 2H), 3.32 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO):d=164.1, 162.0, 157.9, 136.7, 133.5, 132.0, 130.2, 129.3, 121.6, 117.3,117.0, 106.8, 100.4, 69.3, 55.9 ppm; HRMS-ESI: m/z [M+H]+ calcd forC₁₇H₁₇BrNO₄: 378.0341, found: 378.0340.

(E)-N-Hydroxy-2-(4-methoxybenzyloxy)-4-methoxycinnamide (13d)

Following the procedure as described for 13a, reaction of 12d (2.20 g,7.00 mmol) in THF (40 mL) with ethyl chloroformate (1.86 mL, 10.51 mmol)and Et₃N (2.80 mL, 10.51 mmol) gave 13d (1.04 g, 45%) as a white solid:mp: 145-150° C.; ¹H NMR (500 MHz, [D6]acetone): d=7.98 (d, J=15.8 Hz,1H), 7.61 (d, J=8.4 Hz, 1H), 7.55 (d, J=8.6 Hz, 2H), 7.07 (d, J=8.6 Hz,2H), 6.81 (d, J=2.2 Hz, 1H), 6.67 (dd, J=8.6, 2.2 Hz, 1H), 6.64 (d,J=15.8 Hz, 1H), 5.27 (s, 2H), 3.93 (s, 3H), 3.92 ppm (s, 3H); ¹³C NMR(125 MHz, [D6]DMSO): d=162.5, 159.7, 158.6, 135.6, 129.0, 128.8, 116.8,114.4, 113.6, 105.8, 99.5, 69.9, 54.5, 54.3 ppm; HRMS-ESI: m/z [M+H]+calcd for C₁₈H₂₀NO₅: 330.1341, found: 330.1341.

(E)-N-Hydroxy-2-[(naphthalen-4-yl)methoxy]-4-methoxycinnamide (13e)

Following the procedure as described for 13a, reaction of 12e (2.82 g,8.44 mmol) in THF (40 mL) with ethyl chloroformate (2.24 mL, 12.67 mmol)and Et₃N (3.38 mL, 12.67 mmol) gave 13e (1.38 g, 47%) as a white solid:mp: 152-165° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.55 (s, 1H), 8.84 (s,1H), 8.13 (d, J=8.2 Hz, 1H), 7.98 (m, 2H), 7.94 (d, J=8.2 Hz, 1H), 7.69(d, J=6.7 Hz, 1H), 7.61 (d, J=16.1 Hz, 1H), 7.55 (m, 2H), 7.45 (d, J=8.5Hz, 1H), 6.90 (s, 1H), 6.60 (d, J=8.5 Hz, 1H), 6.30 (d, J=16.1 Hz, 1H),5.65 (s, 2H), 3.80 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO): d=163.9,162.2, 158.1, 133.8, 133.2, 132.7, 131.6, 129.3, 129.0, 128.7, 127.1,127.0, 126.5, 125.9, 124.3, 117.0, 106.9, 100.4, 68.7, 55.9 ppm;HRMS-ESI: m/z [M+H]+ calcd for C₂₁H₂₀NO₄: 350.1392, found: 350.1390.

(E)-N-Hydroxy-2-(2-(4-methoxyphenoxyoxy)ethoxy)-4-methoxycinnamide (18a)

Following the procedure described for 8a, reaction of 17a (900 mg, 2.61mmol) in THF (10 mL) with ethyl chloroformate (424 mg, 3.92 mmol) andEt3N (0.73 mL, 5.22 mmol) gave 18a (497 mg, 53%) as a white solid: mp:110-115° C.; ¹H NMR (500 MHz, [D6]acetone): d=10.12 (s, 1H), 8.63 (s,1H), 7.85 (d, J=15.8 Hz, 1H), 7.49 (d, J=8.5 Hz, 1H), 6.95 (d, J=8.1 Hz,2H), 6.86 (d, J=8.1 Hz, 2H), 6.68 (d, J=2.4 Hz, 1H), 6.57 (dd, J=2.4,8.5 Hz, 1H), 6.54 (d, J=15.8 Hz, 1H), 4.42 (m, 2H), 4.38 (m, 2H), 3.83(s, 3H), 3.73 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO): d=162.1, 158.4,158.3, 154.1, 152.8, 133.7, 129.4, 117.2, 116.9, 116.2, 115.1, 113.2,107.0, 100.0, 67.7, 67.3, 60.4, 55.9, 55.8 ppm; HRMS-EI: m/z [M]+ calcdfor C₁₉H₂₁NO₆: 359.1369, found: 359.1364.

(E)-N-Hydroxy-2-(2-(4-methoxyphenoxyoxy)propoxy)-4-methoxycinnamide(18b)

Following the procedure described for 8a, reaction of 17b (300 mg, 0.84mmol) in THF (10 mL) with ethyl chloroformate (136 mg, 1.26 mmol) andEt₃N (0.23 mL, 1.68 mmol) gave 18b (191 mg, 61%) as a white solid: mp:115-120° C.; ¹H NMR (500 MHz, [D6]acetone): d=10.60 (s, 1H), 8.86 (s,1H), 7.57 (d, J=15.9 Hz, 1H), 7.41 (d, J=8.6 Hz, 1H), 6.86 (d, J=9.2 Hz,2H), 6.82 (d, J=9.2 Hz, 2H), 6.60 (d, J=2.3 Hz, 1H), 6.54 (dd, J=2.3,8.6 Hz, 1H), 6.38 (d, J=15.9 Hz, 1H), 4.18 (t, J=6.2 Hz, 2H), 4.07 (t,J=6.2 Hz, 2H), 3.75 (s, 3H), 3.66 (s, 3H), 2.19 ppm (q, J=6.2 Hz, 2H);¹³C NMR (125 MHz, [D6]DMSO): d=164.2, 162.1, 158.7, 153.9, 152.9, 134.0,130.1, 117.3, 116.7, 115.9, 115.1, 106.6, 99.6, 65.5, 65.2, 55.9, 55.8,29.1 ppm; HRMS-ESI: m/z [M+Na]+ calcd for C₂₀H₂₃NNaO₆: 396.1408, found:396.1418.

(E)-N-Hydroxy-2-(2-(4-methoxyphenoxyoxy)butoxy)-4-methoxycinnamide (18c)

Following the procedure described for 8a, reaction of 17c (250 mg, 0.67mmol) in THF (10 mL) was treated with ethyl chloroformate (109 mg, 1.00mmol) and Et3N (0.19 mL, 1.34 mmol) gave 18c (166 mg, 64%) as a whitesolid: mp: 82-88° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.62 (s, 1H), 9.46(s, 1H), 7.57 (d, J=15.9 Hz, 1H), 7.40 (d, J=8.4 Hz, 1H), 6.83 (d, J=9.4Hz, 2H), 6.79 (d, J=9.4 Hz, 2H), 6.56 (s, 1H), 6.52 (d, J=8.4 Hz, 1H),6.35 (d, J=15.9 Hz, 1H), 4.06 (t, J=5.7 Hz, 2H), 3.93 (t, J=5.7 Hz, 2H),3.74 (s, 3H), 3.64 (s, 3H), 1.86 ppm (m, 4H); ¹³C NMR (125 MHz,[D6]DMSO): d=164.2, 162.1, 158.8, 153.8, 153.1, 134.0, 129.9, 117.2,116.7, 115.8, 115.1, 106.5, 99.6, 68.3, 68.0, 55.9, 55.8, 26.1, 25.8ppm; HRMS-ESI: m/z [M⁻H]⁻ calcd for C₂₁H₂₄NO₆: 386.1604, found:386.1609.

(E)-N-Hydroxy-2-(2-(4-methoxyphenoxyoxy)pentyloxy)-4-methoxycinnamide(18d)

Following the procedure described for 8a, reaction of 17d (200 mg, 0.52mmol) in THF (10 mL) with ethyl chloroformate (85 mg, 0.78 mmol) andEt₃N (0.15 mL, 1.04 mmol) gave 18d (118 mg, 57%) as a colorless liquid:¹H NMR (500 MHz, [D6]acetone): d=7.82 (d, J=15.7 Hz, 1H), 7.47 (d, J=8.4Hz, 1H), 6.86 (d, J=9.4 Hz, 2H), 6.84 (d, J=15.7 Hz, 1H), 6.82 (d, J=9.4Hz, 2H), 6.60 (d, J=2.2 Hz, 1H), 6.54 (dd, J=2.2, 8.4 Hz, 1H), 4.12 (t,J=6.4 Hz, 2H), 3.97 (t, J=6.4 Hz, 2H), 3.82 (s, 3H), 3.71 (s, 3H), 1.93(m, 2H), 1.84 (m, 2H), 1.69 ppm (m, 2H); ¹³C NMR (125 MHz, [D6]DMSO):d=162.4, 159.1, 153.9, 153.3, 135.1, 129.8, 116.8, 115.4, 114.5, 105.7,99.0, 68.2, 68.1, 54.9, 28.9, 28.7, 22.6 ppm; HRMS-ESI: m/z [M_H]_calcdfor C₂₂H₂₆NO₆: 400.1760, found: 400.1766.

(E)-N-Hydroxy-4-methoxy-2-phenylcinnamide (22a)

Following the procedure described for 8a, reaction of 21a (800 mg, 3.15mmol) in THF (10 mL) with ethyl chloroformate (512 mg, 4.73 mmol) andEt₃N (0.88 mL, 6.30 mmol) gave 22a (355 mg, 42%) as a white solid: mp:100-102° C.; ¹H NMR (500 MHz, [D6]acetone): d=8.67 (br s, 1H), 7.66 (d,J=8.2 Hz, 1H), 7.55 (d, J=15.5 Hz, 1H), 7.47 (m, 2H), 7.39 (m, 1H), 7.33(d, J=8.4 Hz, 2H), 6.98 (dd, J=2.5, 8.7 Hz, 1H), 6.88 (d, J=2.5 Hz, 1H),6.41 (d, J=15.5 Hz, 1H), 3.89 ppm (s, 3H); ¹³C NMR (125 MHz,[D6]acetone): d=164.7, 161.3, 145.1, 141.1, 138.6, 130.5, 129.1, 128.8,128.4, 128.1, 126.4, 117.3, 115.9, 114.9, 114.7, 55.8 ppm; HRMS-ESI: m/z[M+Na]+ calcd for C₁₆H₁₅NNaO₃: 292.0950, found: 292.0944.

(E)-N-Hydroxy-4-methoxy-2-(4-bromophenyl)cinnamide (22b)

Following the procedure described for 8a, reaction of 21b (500 mg, 1.51mmol) in THF (10 mL) with ethyl chloroformate (245 mg, 2.27 mmol) andEt₃N (0.42 mL, 3.02 mmol) gave 22b (204 mg, 39%) as a white solid: mp:141-144° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.64 (s, 1H), 8.90 (s, 1 H),7.65 (d, J=8.2 Hz, 2H), 7.63 (d, J=8.7 Hz, 1H), 7.25 (d, J=8.2 Hz, 2H),7.22 (d, J=15.6 Hz, 1H), 7.02 (dd, J=2.1, 8.7 Hz, 1H), 6.84 (d, J=2.1Hz, 1H), 6.28 (d, J=15.6 Hz, 1H), 3.80 ppm (s, 3H); ¹³C NMR (125 MHz,[D6]DMSO): d=163.4, 160.3, 142.6, 139.4, 136.4, 132.1, 131.8, 128.3,125.6, 121.7, 118.6, 115.4, 115.1, 55.9 ppm. HRMS-ESI: m/z [M+Na]+ calcdfor C₁₆H1₄BrNNaO₃: 370.0055, found: 370.0049.

(E)-N-Hydroxy-4-methoxy-2-(naphthalen-1-yl)cinnamide (22 c)

Following the procedure described for 8a, reaction of 21c (1.00 g, 3.29mmol) in THF (15 mL) with ethyl chloroformate (533 mg, 4.93 mmol) andEt₃N (0.92 mL, 6.58 mmol) gave 22c (619 mg, 59%) as a white solid: mp:125-127° C.; ¹H NMR (500 MHz, [D6]DMSO): d=8.00 (d, J=8.2 Hz, 2H), 7.74(d, J=8.8 Hz, 1H), 7.59 (t, J=7.9 Hz, 1H), 7.52 (t, J=7.2 Hz, 1H), 7.42(t, J=7.9 Hz, 1H), 7.33 (d, J=6.8 Hz, 1H), 7.30 (d, J=8.4 Hz, 1H), 7.11(dd, J=2.6, 8.8 Hz, 1H), 6.83 (d, J=15.6 Hz, 1H), 6.82 (d, J=2.5 Hz,1H), 6.25 (d, J=15.6 Hz, 1H), 3.79 ppm (s, 3H); ¹³C NMR (125 MHz,[D6]DMSO): d=163.3, 160.3, 142.4, 137.9, 136.2, 133.6, 132.0, 128.8,128.6, 127.7, 127.5, 127.0, 126.9, 126.6, 125.9, 118.0, 116.3, 115.1,55.9 ppm; HRMS-ESI: m/z [M+Na]+ calcd for C₂₀H₁₇NNaO₃: 342.1106, found:342.1101.

(E)-N-Hydroxy-4-methoxy-2-(biphenyl-4-yl)cinnamide (22d)

Following the procedure described for 8a, reaction of 21d (800 mg, 2.42mmol) in THF (15 mL) with ethyl chloroformate (393 mg, 3.64 mmol) andEt₃N (0.68 mL, 4.84 mmol) gave 22d (326 mg, 39%) as a white solid: mp:76-79° C.; ¹H NMR (500 MHz, [D6]DMSO): d=7.76 (d, J=8.1 Hz, 1H), 7.73(d, J=7.7 Hz, 2H), 7.65 (d, J=8.7 Hz, 1H), 7.48 (t, J=7.7 Hz, 2H), 7.39(d, J=8.1 Hz, 3H), 7.35 (d, J=15.0 Hz, 1H), 7.02 (dd, J=2.6, 8.7 Hz,1H), 6.90 (d, J=2.6 Hz, 1H), 6.32 (d, J=15.0 Hz, 1H), 3.82 ppm (s, 3H);¹³C NMR (125 MHz, [D6]DMSO): d=163.5, 160.4, 143.5, 140.0, 139.9, 139.3,136.9, 130.6, 129.5, 128.3, 128.1, 127.2, 127.1, 125.6, 118.3, 115.4,114.9, 55.9 ppm; HRMS-ESI: m/z [M+Na]+ calcd for C₂₂H₁₉NNaO₃: 368.1263,found: 368.1257.

(E)-N-Hydroxy-4-methoxy-2-(4-phenoxyphenyl)cinnamide (22e)

Following the procedure described for 8a, reaction of 21e (800 mg, 2.31mmol) in THF (15 mL) with ethyl chloroformate (374 mg, 3.47 mmol) andEt₃N (0.65 mL, 4.62 mmol) gave 22e (417 mg, 50%) as a white solid: mp:75-78° C.; ¹H NMR (500 MHz, [D6]DMSO): d=7.61 (d, J=8.7 Hz, 1H), 7.42(t, J=8.1 Hz, 1H), 7.42 (d, J=15.8 Hz, 1H), 7.30 (d, J=8.5 Hz, 3H), 7.18(t, J=7.4 Hz, 1H), 7.10 (d, J=8.0 Hz, 2H), 7.05 (d, J=8.5 Hz, 2H), 6.99(dd, J=2.6, 8.7 Hz, 1H), 6.85 (d, J=2.6 Hz, 1H), 6.28 (d, J=15.8 Hz,1H), 3.80 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO): d=163.5, 160.3,157.1, 156.5, 143.3, 136.9, 135.0, 131.6, 130.7, 128.3, 125.7, 124.5,119.8, 118.3, 118.2, 115.5, 114.7, 55.8 ppm; HRMS-ESI: m/z [M+Na]+ calcdfor C₂H₁₉NNaO₄: 384.1212, found: 384.1206.

(E)-N-Hydroxy-4-methoxy-2-(4-benzoylphenyl)cinnamide (22f)

Following the procedure described for 8a, reaction of 21 f (900 mg, 2.51mmol) in THF (20 mL) with ethyl chloroformate (406 mg, 3.77 mmol) andEt₃N (0.71 mL, 5.02 mmol) gave 22 f (487 mg, 52%) as a white solid: mp:71-73° C.; ¹H NMR (500 MHz, [D6]DMSO): d=7.83 (d, J=8.0 Hz, 2H), 7.78(d, J=7.6 Hz, 2H), 7.68 (d, J=7.3 Hz, 1H), 7.67 (d, J=7.6 Hz, 1H), 7.58(t, J=7.6 Hz, 2H), 7.50 (d, J=8.0 Hz, 2H), 7.29 (d, J=15.6 Hz, 1H), 7.06(dd, J=2.3, 8.6 Hz, 1H), 6.92 (d, J=2.3 Hz, 1H), 6.31 (d, J=15.6 Hz,1H), 3.82 ppm (s, 3H); ¹³C NMR (125 MHz, [D6]DMSO): d=195.8, 163.4,160.4, 144.5, 142.8, 137.5, 136.5, 136.4, 133.2, 130.3, 130.2, 130.1,129.1, 128.5, 125.6, 118.8, 115.4, 55.9 ppm; HRMS-ESI: m/z [M+Na]+ calcdfor C₂₃H₁₉NNaO₄: 396.1212, found: 396.1206.

(E)-N-Hydroxy-4-methoxy-2-(dibenzofuran-4-yl)cinnamide (22g)

Following the procedure described for 8a, reaction of 21g (1.00 g, 2.91mmol) in THF (20 mL) with ethyl chloroformate (470 mg, 4.36 mmol) andEt₃N (0.82 mL, 5.82 mmol) gave 22g (532 mg, 51%) as a white solid: mp:158-161° C.; ¹H NMR (500 MHz, [D6]DMSO): d=8.21 (d, J=7.7 Hz, 1H), 8.19(d, J=7.7 Hz, 1H), 7.74 (d, J=8.5 Hz, 1H), 7.60 (d, J=8.2 Hz, 1H), 7.49(q, J=7.5 Hz, 2H), 7.41 (d, J=7.5 Hz, 1H), 7.38 (d, J=7.2 Hz, 1H), 7.11(dd, J=2.5, 8.5 Hz, 1H), 7.10 (d, J=15.6 Hz, 1H), 7.01 (d, J=2.5 Hz,1H), 6.30 (d, J=15.6 Hz, 1H), 3.82 ppm (s, 3H); ¹³C NMR (125 MHz,[D6]DMSO): d=163.3, 160.4, 156.0, 153.4, 138.5, 136.2, 129.2, 128.3,127.9, 126.5, 124.5, 124.3, 124.0, 123.7, 121.8, 121.4, 118.3, 116.3,115.4, 112.3, 55.9 ppm; HRMS-ESI: m/z [M+Na]+ calcd for C₂₂H₁₇NNaO₄:382.1055, found: 382.1050.

(E)-N-Hydroxy-4-propoxy-2-phenylcinnamide (27a)

NaOH (120 mg, 3.01 mmol) in 50% NH₂OH(aq) (2 mL) in an ice bath wasadded to a solution of 26a (170 mg, 0.60 mmol) in MeOH/THF (1 mL: 1 mL).The resulting solution was then warmed to room temperature and stirredfor an additional 3 h. The reaction was diluted with distilled water (50mL), acidified with 1n HCl(aq) to pH 6-7, and extracted with EtOAc (25mL×3). The organic layer was dried (Na₂SO₄) and filtered, and thesolvent was removed in vacuo. The residue was purified by silica gelchromatography (MeOH/CH₂Cl₂, 3:97) to give 27a (90 mg, 51%) as a whitesolid: mp: 147-150° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.22 (s, 1H),7.69 (d, J=8.5 Hz, 1H), 7.54 (d, J=15.4 Hz, 1H), 7.42 (m, 3H), 7.33 (m,2H), 6.97 (dd, J=2.5, 8.5 Hz, 1H), 6.87 (d, J=2.5 Hz, 1H), 6.39 (d,J=15.4 Hz, 1H), 4.03 (t, J=6.6 Hz, 2H), 1.78 (m, 2H), 1.01 ppm (t, J=7.5Hz, 3H); ¹³C NMR (125 MHz, [D6]DMSO): d=163.5, 159.8, 140.0, 140.2,136.9, 130.0, 128.8, 128.2, 128.1, 125.4, 118.0, 116.0, 115.1, 69.7,22.5, 10.8 ppm; HRMS-ESI: m/z [M+Na]+ calcd for C₁₈H₁₉NNaO₃: 320.1263,found: 320.1257.

(E)-N-Hydroxy-4-butoxy-2-phenylcinnamide (27b)

NaOH (100 mg, 2.50 mmol) in 50% NH₂OH(aq) (2 mL) in an ice bath wasadded to a solution of 26b (162 mg, 0.50 mmol) in MeOH/THF (1 mL: 1 mL).Following the procedure as described for 27a gave 27b (88 mg, 57%) as awhite solid: mp: 140-144° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.61 (s,1H), 8.87 (s, 1H), 7.61 (d, J=8.7 Hz, 1H), 7.45 (d, J=15.7 Hz, 1H), 7.42(m, 2H), 7.28 (m, 3H), 6.99 (dd, J=2.3, 8.7 Hz, 1H), 6.82 (d, J=2.3 Hz,1H), 6.28 (d, J=15.7 Hz, 1H), 4.02 (t, J=7.4 Hz, 2H), 1.69 (m, 2H), 1.41(m, 2H), 0.91 ppm (t, J=7.4 Hz, 3H); ¹³C NMR (125 MHz, [D6]DMSO):d=163.5, 159.8, 144.0, 140.2, 136.9, 130.0, 128.8, 128.1, 125.4, 118.0,115.9, 115.2, 67.9, 31.2, 19.2, 14.2 ppm; HRMS-ESI: m/z [M+Na]+ calcdfor C₁₉H₂₁NNaO₃: 334.1419, found: 334.1414.

(E)-N-Hydroxy-4-pentoxy-2-phenylcinnamide (27c)

NaOH (100 mg, 2.50 mmol) in 50% NH₂OH(aq) (2 mL) in an ice bath wasadded to a solution of 26c (169 mg, 0.50 mmol) in MeOH/THF (1 mL: 1 mL).Following the procedure as described for 27a gave 27c (86 mg, 53%) as awhite solid: mp: 121-124° C.; ¹H NMR (500 MHz, [D6]DMSO): d=10.61 (s,1H), 9.47 (s, 1H), 7.62 (d, J=8.7 Hz, 1H), 7.47 (d, J=15.6 Hz, 1H), 7.46(m, 1H), 7.42 (m, 1H), 7.29 (m, 3H), 7.00 (dd, J=2.6, 8.7 Hz, 1H), 6.83(d, J=2.6 Hz, 1H), 6.29 (d, J=15.6 Hz, 1H), 4.02 (t, J=6.5 Hz, 2H), 1.71(m, 2H), 1.36 (m, 4H), 0.88 ppm (t, J=6.5 Hz, 3H); ¹³C NMR (125 MHz,[D6]DMSO): d=163.5, 159.8, 158.4, 144.0, 140.2, 136.9, 130.0, 128.8,128.1, 128.0, 125.4, 118.0, 115.9, 115.2, 68.2, 28.8, 28.1, 22.3, 14.4ppm; HRMS-ESI: m/z [M+Na]+ calcd for C₂₀H₂₃NNaO₃: 348.1576, found:348.1570.

(E)-N-Hydroxy-2,4-diphenylcinnamide (27d)

NaOH (191 mg, 4.78 mmol) in 50% NH₂OH(aq) (4 mL) in an ice bath wasadded to a solution of 32 (300 mg, 0.96 mmol) in MeOH/THF (2 mL:2 mL)was added. Following the procedure as described for 27a gave 27d (133mg, 44%) as a white solid: mp: 135-137° C.; ¹H NMR (500 MHz, [D6]DMSO):d=7.64 (d, J=15.4 Hz, 1H), 7.74 (d, J=7.4 Hz, 2H), 7.71 (dd, J=1.5, 8.2Hz, 1H), 7.63 (d, J=1.5 Hz, 1H), 7.49 (m, 3H), 7.45 (m, 1H), 7.42 (m,3H), 7.32 (m, 1H), 6.58 ppm (d, J=15.4 Hz, 1H); ¹³C NMR (125 MHz,[D6]DMSO): d=163.1, 142.9, 141.4, 140.2, 139.6, 136.8, 132.2, 130.2,129.5, 129.4, 128.9, 128.4, 128.1, 127.4, 127.3, 126.7, 120.5 ppm;HRMS-ESI: m/z [M+Na]+ calcd for C₂₁H₁₇NNaO₂: 338.1157, found: 338.1151.

Example 3. Initial Biological Evaluation

The para-benzyl N-hydroxycinnamides 8a-f and ortho-benzylN-hydroxycinnamides 13a-e were screened for inhibitory activity againstHDAC8 at a concentration of 1 μm, using SAHA as a reference compound.Ortho-substituted series 13a-e showed higher potency thanparasubstituted 8a-f. Compounds 13a, 13c, and 13d were further evaluatedfor IC₅₀ values against HDAC8, as well as against HeLa nuclear extractthat contained mainly HDACs1-3, to analyze isoform selectivity (Table4).

TABLE 4 Inhibition of HDAC8 and HeLa nuclear HDAC by compounds 13a, 13c,and 13d.

IC₅₀ [nM]^([a]) HeLa Compd R HDAC8 HDAC 13a H 206.5 ± 13.4 >10000 13c Br613.5 ± 60.8 >10000 13d OCH₃ 397.2 ± 12.7 >10000 SAHA 1855.1 ± 0.1  41.7± 3.2 ^([a])Data are expressed as the mean _SD of three determinations.

These compounds appeared to prefer HDAC8 (IC₅₀=206-613 nm) over otherclass I isoforms (IC₅₀>10 000 nm), suggesting that the ortho-orientedbenzyl group may exploit the secondary hydrophobic surface pocket ofHDAC8.

Next, N-hydroxycinnamides 18a-d were synthesized with various linkerchains added to the ortho-aryl groups, as well as ortho-phenylN-hydroxycinnamide 22a with a shortened linker chain (Table 5, Table 6).

TABLE 5 Inhibition of HDAC8 and HeLa nuclear HDAC by compounds withvarying chain length (n).

IC₅₀ [nM]^([a]) Compound n HDAC8 HeLa HDAC 18a 2 122.5 ± 3.5 >10000 18b3 191.3 ± 2.2 >10000 18c 4 112.1 ± 2.2 >10000 18d 5 200.3 ± 6.5 >10000PC1450451 —  55.7 ± 0.7 >10000 ^([a])Data are expressed as the mean SDof three determinations.

Although the enzyme inhibitory activity of compounds 18a-d (IC₅₀=112-191nm) were all increased relative to the original benzyl-substitutedseries, compound 22a with no flexible linker showed the best HDAC8inhibitory activity (IC50=72 nm), which was compatible to PCI34051(IC₅₀=⁵⁶ nm).

We further performed molecular docking for HDAC8 crystal structure withcompound 22a and PCI34051, which showed that further hydrophobicincorporation into the ortho-phenyl moiety of compound 22a maypotentially make additional contacts to the active site of HDAC8. Totest the molecular modeling results, we synthesized compounds 22b-g and27a-d and examined the resulting compounds for enzyme inhibitoryactivity. Compounds 22b, 22d, 22 f, and 22g showed inhibitory activitiessuperior to PCI34051 for HDAC8; in particular, 22b and 22d were aroundten- and two-fold more potent, respectively. Compound 22b was 13-foldmore potent than 22a, suggesting that introduction of a para-bromo groupresults in a significant increase in binding affinity. Compounds 22d and22 f-g were two- to threefold more potent than 22a, indicating that theintroduction of additional coplanar phenyl group leads to an increase inactivity. Compound 22e was three-fold less potent than 22a, suggestingthat the dramatic loss of activity is perhaps due to the twisted phenylconformation adopted in ether moiety. The para-alkyl-substituted phenylN-hydroxycinnamides 27a-d were approximately two- to fourfold lesspotent than 22a, suggesting that increasing the carbon chain lengthattached to the para-oxygen position weakens binding affinity.

TABLE 6 Inhibition of HDAC8 and HeLa nuclear HDAC by compounds 22a-g and27a-d.

IC₅₀ [nM]^([a]) Com- HeLa pound R¹ R² HDAC8 HDAC 22a OCH₃

72.4 ± 0.1 >10000 22b OCH₃

 5.7 ± 0.1 >10000 22c OCH₃

78.0 ± 4.3 >10000 22d OCH₃

27.2 ± 3.1 >10000 22e OCH₃

173.8 ± 5.9  >10000 22f OCH₃

41.8 ± 3.3 >10000 22g OCH₃

47.7 ± 0.7 >10000 27a OC₃H₇

132.6 ± 12.6 >10000 27b OC₄H₉

289.2 ± 30.1 >10000 27c OC₅H₁₁

186.4 ± 59.8 >10000 27d C₆H₅

174.9 ± 0.2  >10000 PCI34051 — — 55.7 ± 0.7 >10000 ^([a])Data areexpressed as the mean SD of three determinations.

We evaluated the potent HDAC8 inhibitors 22b, 22d, 22 f, and 22g foranti-proliferative activity in human lung cancer cell lines, includingA549 cells, H1299 cells, CL-1 cells, and CL1-5 cells using SAHA andPCI34051 as reference compounds (Table 7).

TABLE 7 Cytotoxicity of compounds 22b, 22d, 22 f, and 22g againstvarious lung cancer cell lines. IC₅₀ [nM]^([a]) Compound A549 H1299Cl1-1 Cl1-5 22b >10 >10 >10 >10 22d 7.9 ± 1.5 7.2 ± 0.7 >10 7.0 ± 1.522f >10 8.4 ± 0.2 >10 >10 22g >10 6.6 ± 0.7 8.5 ± 1.2 8.7 ± 0.1 SAHA 1.5± 0.7 4.9 ± 0.3 2.9 ± 0.5 6.2 ± 0.6 PCI34051 >10 >10 >10 >10 ^([a])Dataare expressed as the mean _SD of three determinations.

Compound 22b exhibited low cytotoxicity in all four cancer cell lines.In addition, compounds 22d and 22g showed higher cytotoxicity thanPCI34051 in three cancer cell lines. Although compound 22d showedmoderate anti-proliferative effects in human lung cancer A549 and H1299cells, it exhibited activity similar to that of SAHA in CL1-5 cells withno significant cytotoxicity in normal IMR-90 cells. The HDAC8 level inCL1-5 is higher than that in H1299 and A549. To verify whether thesecompounds were HDAC8-selective, we tested inhibitory activities ofcompounds 22b and 22d against a panel of purified HDACs, including classI (HDAC1, 2, 3),[28] class II (HDAC4, 6, 10)[29] and class IV(HDAC11)[30] enzymes. Table 8 shows that these compounds were inactivetoward most other HDACs and had limited activity against HDAC1 and 3.

TABLE 8 Inhibition of class I (1, 2, 3), II (4, 6, 10), and IV (11)HDACs by compounds 22b, 22d, and PCI34051. IC₅₀ [nM]^([a]) Compound 1 23 4 6 10 11 22b 4.5 ± 0.1 >20 4.8 ± 0.5 >20 >20 >20 >20 22d 3.0 ±0.2 >20 3.0 ± 0.1 >20 >20 >20 >20 PCI34051 7.5 ±0.4 >20 >20 >20 >20 >20 >20 ^([a])Data are expressed as the mean _SD ofthree determinations.

Example 4. Inhibition of HDAC8 Reactivates p53 and Abrogates LeukemiaStem Cell Activity in CBFβ-SMMHC Associated Acute Myeloid Leukemia

Introduction.

Acute myeloid leukemia (AML) arises from disordered hematopoiesis as aconsequence of multiple cooperative mutations or alternations disruptingdifferentiation, proliferation and survival programs in hematopoieticprogenitors. Recurrent chromosomal abnormalities in AML involvetranscription factor fusion proteins that contribute to unique etiologyand prognosis [1]. The core-binding factor (CBF) transcription complexis a regulator of hematopoietic development and a frequent target ofleukemia associated chromosomal translocation or inversion [2]. Afunctional CBF complex consists of a DNA-binding a subunit (RUNX1,RUNX2, RUNX3) and a non-DNA binding β subunit (CBFβ), which increasesDNA-binding affinity and may be essential for transactivation activity[3-5]. Chromosomal 16 inversion, inv(16)(p13.1q22) ort(16;16)(p13.1;q22) is found in approximately 5-12% of AML patients andis associated with the FAB M4Eo AML subtype [6-11]. This inversionresults in fusion of CBFB with the MYH11 gene, which encodes a smoothmuscle myosin heavy chain (SMMHC) protein [12]. The CBFB-MYH11 fusiongene encodes a fusion protein CBFβ-SMMHC, which retains the RUNX1binding interface of CBFβ and the coiled-coil rod region of SMMHC. Aknock-in allele for Cbfb-MYH11 was previously generated in mice andresultant Cbfb-MYH11 heterozygotes showed a profound defect indefinitive hematopoiesis and exhibited lethal hemorrhage at E12.5 [13].These phenotypes are identical to those of Runx1- or Cbfb-null mice[14,15], suggesting that CBFβ-SMMHC is a dominant inhibitor of CBFfunction. Using a conditional Cbfb-MYH11 knock-in mouse model, we showedthat CBFβ-SMMHC expression in adult hematopoietic stem cells (HSCs)leads to impaired differentiation of multiple hematopoietic lineages andproduces pre-leukemic stem and progenitor populations at risk foracquiring cooperating alterations required for AML transformation [16].

Dominant inhibition of RUNX1 has been considered the main function ofCBFβ-SMMHC. CBFβ-SMMHC was shown to contain an additional RUNX1 bindingsite within SMMHC near the inversion breakpoint, and thus binds to RUNX1with a much higher affinity than CBFβ [17]. Therefore, it is proposedthat CBFβ-SMMHC transdominantly inhibits RUNX1 function through highaffinity binding and cytoplasmic sequestration [18,19]. Meanwhile,CBFβ-SMMHC was shown to interact with the mSin3A corepressor and histonedeacetylase 8 (HDAC8), supporting an alternative model where CBFβ-SMMHCconverts RUNX1 to a constitutive transcriptional repressor [20,21]. Weshowed that elevated levels of Runx2 expression enhancesCBFβ-SMMHC-mediated leukemic transformation while loss of one Runx2allele reduces and delays leukemogenesis [22]. This genetic evidencesuggests that the leukemogenic function of CBFβ-SMMHC is in factdependent on functional RUNX proteins rather than RUNX inhibition.Studies demonstrated that the high affinity RUNX1 binding domain ofCBFβ-SMMHC is dispensable for leukemogenesis [23]. In addition, RUNX1activity is required for the growth and maintenance of inv(16) AML cells[24,25].

The tumor suppressor p53 is a genomic guardian that centrallycoordinates cellular responses including cell cycle progression, DNArepair, and apoptosis. Genetic mutations that inactivate p53 functionoccur in approximately half of all cases of human cancer; however, theseTP53 mutations are relatively rare in de novo AML (approximately 10%).TP53 mutation in AML is correlated with complex karyotype, drugresistance and dismal outcome [26-28]. Loss of p53 is shown to promoteAML pathogenesis in mice by enabling aberrant self-renewal [29]. Widespectrum post-translational modifications including phosphorylation,acetylation, ubiquitination, methylation, sumoylation and neddylationact to coordinate and modulate specific functions of p53 [30]. Given thelow TP53 mutation rate, alternative mechanisms affecting proteinstability or modifications are expected to be involved in disrupting p53function during AML pathogenesis.

HDACs are a family of enzymes that catalyze the removal of acetylmoieties from ε-amino groups of lysine residues in a variety ofproteins, including histones and transcription factors, and thus playcrucial roles in chromatin remodeling and regulation of gene expression.HDAC8 is a class I HDAC, maps to the X chromosome q13 [31-33], and islikely important for diverse biological functions, including smoothmuscle contraction [34], telomere protection [35], skull morphogenesis[36], and regulation of cohesion dynamics [37]. HDAC8 is highlyexpressed in myeloid and lymphoid leukemia cell lines [33] and is likelyoverexpressed in multiple tumor types, including neuroblastoma, glioma[38] and childhood acute lymphoblastic leukemia [39]. Although HDAC8 hasbeen shown to interact with CBFβ-SMMHC [21], its role in AMLpathogenesis and maintenance remains unclear.

Without being bound by any particular theory, we hypothesized that p53activity is disrupted by the leukemogenic CBFβ-SMMHC fusion protein. Wedemonstrate that CBFβ-SMMHC impairs p53 through a previously unknownmechanism involving post-translational modification by HDAC8. Ourresults provide new molecular insights into the leukemogenic mechanismdriven by inv(16) and highlight the therapeutic opportunity ofreactivating p53 by HDAC8 inhibition.

Experimental Methods

Mice.

All Cbfb^(56M/+) [16] and the Mx1-Cre [58] mice used were backcrossed toC57BL/6 for more than 8 generations. Ai14 Cre reporter tdTomato mice onC57BL/6 background were obtained from the Jackson Laboratory. To induceCBFβ-SMMHC expression, 4-6 week old Mx1-Cre/Cbfb^(56M/+) mice wereinjected with 250 μg of polyinosinic-polycytidylic acid (pIpC)(InvivoGen) every 2 days for 7 doses. Similarly treated Cbfb^(56M/+)littermates without Cre were used as control. Pre-leukemic cells wereisolated from mice 2 weeks after the last dose of pIpC treatment. Forleukemia development, induced mice were monitored up to 6 months andanalyzed when moribund. Transplantation of AML cells (2×10⁶ cells/mouse)was performed via tail vein injection into sub-lethally irradiated (6.5Gy) 6-8-week-old congenic C57BL/6 mice (CD45.1⁺/CD45.2⁺). All mice weremaintained in an AAALAC-accredited animal facility at City of Hope, andall experimental procedures involving mice were performed in accordancewith federal and state government guidelines and establishedinstitutional guidelines and protocols approved by the InstitutionalAnimal Care and Use Committee at Beckman Research Institute of City ofHope.

Human Samples.

Cord blood (CB) samples were provided by Stemcyte (Arcadia, Calif.).Mobilized peripheral blood stem cells (PBSC) were obtained from healthydonors (City of Hope). Inv(16)⁺ AML samples were obtained frompreviously untreated patients at the City of Hope. See Table 6Xfollowing for characteristics of human samples for studies disclosedherein. CD34⁺ cell isolation was performed using magnetic beads(StemCell Technologies, Vancouver, BC, Canada). Leukopheresis sampleswere processed for CD34⁺ cell selection with CliniMACS (MiltenyiBiotech, Germany). All subjects signed an informed consent form. Sampleacquisition was approved by the Institutional Review Boards at the Cityof Hope, in accordance with an assurance filed with and approved by theDepartment of Health and Human Services.

TABLE 9 Characteristics of patient samples Disease FAB Sample State atBlasts Blasts ID Sex Age Diag. Class. Type Collection Risk StatusCytogenetic Other mutation WBC in PB in BM AML020 F 47 AML M4eo PBUntreated Better-risk inv(16) FLT-3 ITD Neg 50.8 67 90 AML021 F 42 AMLM4 BM Untreated Better-risk inv(16) 39.2 60 40 AML033 M 69 AML non- PBUntreated Intermediate inv(16), trisomy 22 6.3 30 98 classified riskAML041 F 56 AML M2 PB Untreated Better-risk inv(16), trisomy 8 38.8 6344 AML111 M 51 AML M2 BM Untreated Intermediate- Inv(16), trisomy 8,13.4 70 75 risk trisomy 21 AML163 M 57 AML M4 PB Relapsed Intermediate-t(16; 16), trisomy 82.8 94 67 risk 21, trisomy 22 AML319 F 46 AML M4 PBUntreated Better-risk CBFB/16q22 1.4  0 rearrangement AML987 M 50 AML M4PB Relapsed Intermediate- t(16; 16), FLT-3 ITD Neg, 64.1 90 risktrisomy22, FLT-3 D835 Pos., CBFB NPM1 Neg., rearrangement C-KIT NegAML1052 F 23 AML M4 BM Relapsed Intermediate- inv(16), trisomy 8, FLT-3ITD Neg, 9.9 64 87 risk trisomy 22 FLT-3 D835 Neg AML1070 F 37 AML M4EoBM Relapsed Better-risk der(16) inv(16) NPM1 neg 2.7  3 30 (p13.1q22)del(16) (q22.1q22.?2) [16]/[22] 44% CBFB rearrangement by FISH AML270 M61 AML PR Untreated Poor-risk Complex FLT-3 ITD Neg 4.4  5 50abnormalities, including 11q23, MLL gain, loss of TP53/17p13.1, add(2),add(5), add(22), ider(11), del(11) AML467 F 61 AML PB UntreatedPoor-risk Complex FLT-3 ITD Neg, 44.7 51 80 abnormalities with FLT-3D835 Neg trisomy 8, trisomy 9 and trisomy 22 AML578 M 38 AML M5b PBRefractory/ Poor-risk Trisomy 8, FLT-3 ITD Pos, 1.3 41  8 Inductiondel(9q), t(2; 18), FLT-3 D835 Neg, failure trisomy 13 NPM1 Neg AML865 F60 AML PB Untreated Poor-risk Normal FLT-3 ITD Pos, 86.3 90 90cytogenetics FLT-3 D835 Neg, JAK2 Neg

Cell Transduction and Flow Cytometry.

Bone marrow cells were isolated as previously described [59]. Cellculture employed conditions well known in the art. Bone marrow cells or32D cells were transduced with MSCV-ires-GFP (MIG) based retroviruses orlentiviruses (pLKO.1 or HIV-7) [40] by spinoculation in the presence of5 ug/mL polybrene (American Bioanalytical, Natick, Mass.). Human CD34⁺cells were transduced with pLKO.1 lentivirus by two rounds ofspinoculation. Cell sorting was performed on a 4-laser, 15-detectorFACSAria-III or a 6-laser, 18-detector FACSAria II SORP (BD Bioscience,San Jose, Calif.). Cell proliferation and apoptosis assays wereconducted as well known in the art.

Immunoprecipitation (IP) and Western Blotting.

Cells were lysed in RIPA buffer containing protease inhibitor cocktail(Roche) and MG132. Antibodies used for IP were conjugated with proteinA/G beads using the antibody cross-linking kit (Pierce Biotechnology,Rockford, Ill.) following manufacturer's protocol. For Western blot,proteins were resolved in 10% SDS-PAGE. The antibodies used inducedanti-FLAG (Sigma), anti-HDAC8, anti-CBFβ (Santa Cruz), anti-p53 (DO-1),anti-Ac-p53 (K379) (Cell Signaling), anti-p53 (Cell signaling) andanti-β-actin (Sigma). Horseradish peroxidase-conjugated anti-rabbit oranti-mouse secondary antibodies (Jackson ImmunoResearch, West Grove Pa.)were used, followed by detection using the SuperFemto kit (PierceBiotechnology, Rockford, Ill.).

DUOLINK® In Situ Proximity Ligation Assay (PLA).

The DUOLINK® kit (Sigma, St. Louis, Mo.) was used to perform in situproximity ligation assay (PLA) following manufacturer suggestedprocedures. Antibodies used included mouse anti-CBFβ (Santa Cruz),rabbit anti-Ac-p53 (K379) (Cell Signaling) and rabbit anti-p53 (CellSignaling). Slides were mounted using in anti-fade media containing DAPI(Santa Cruz) and imaged using a Zeiss upright LSM 510 2-photon confocalmicroscope.

Statistics.

Statistical analyses were performed with Student's t test or analysis ofvariance (ANOVA) for normal distribution. Mann-Whitney U tests wereperformed when normal distribution was not satisfied. p value less than0.05 was considered statistically significant (*p<0.05; **p<0.01;***p<0.001).

Results and Discussion

CBFβ-SMMHC Expression Impairs Activation and Acetylation of p53.

Without being bound by any particular theory, we hypothesized thatCBFβ-SMMHC exerts its leukemogenic function through affecting molecularand cellular processes operating to safeguard genome integrity. Sincep53 represents the master genomic guardian, we tested whether CBFβ-SMMHCfusion protein impairs p53 function. We generated myeloid progenitor 32Dcell lines (p53 wild type) expressing CBFβ-SMMHC (CM) or CBFβ (allFLAG-tagged) through MSCV-ires-GFP (MIG) retroviral transduction, andsorting of GFP⁺ transduced cells. We performed quantitative RT-PCRanalysis to analyze induction of p53 target genes including p21 Cdkn1a,Mdm2, Bid, Bax, and Gadd45b in 32D cells after γ-irradiation (IR) (3 Gy,24 h). Compared to control cells expressing CBFβ, CM-expressing cellspartially or completely inhibited induction of p53 targets (FIG. 1A).

Acetylation of p53 protein is important for protein stabilization andits transcriptional activity. Using western blot analysis with anantibody against an acetylated (Ac)-form of p53 (K379), we tested theeffect of CM on p53 acetylation in response to IR (3 Gy)-induced DNAdamage. The level of Ac-p53 was markedly reduced in CM-expressing cellscompared to control cells expressing CBFβ at all time points (2, 4, 6,12 h) analyzed (FIG. 1B). We have established a conditional knock-inmouse model Cbfb^(56M/+)/Mx1-Cre can be efficiently induced to expressCM by pIpC [16]. We examined total p53 and Ac-p53 levels in primary bonemarrow (BM) progenitor cells isolated from pre-leukemicCbfb^(56M/+)/Mx1-Cre or control Cbfb^(56M/+) mice 2 weeks after pIpCinduction. Likewise, we find that induction of Ac-p53 level is largelyreduced in pre-leukemic progenitor cells expressing endogenous levels ofCM (FIG. 1C). Time course analysis revealed that the initial acetylationof p53 can occur (2 h post-IR), however, p53 is rapidly deacetylated inCM-expressing progenitors (FIG. 1C). To rule out possible secondarypre-leukemic effects not directly caused by CM-expression, we introducedCre through MIG retroviral transduction of BM progenitors fromCbfb^(56M/+) mice. Transduced cells were sorted 48 h later and testedfor IR (3 Gy)-induced p53 acetylation. CM expression was efficientlyinduced in MIG-Cre-transduced progenitor cells and readily led to markedreduction in the Ac-p53 level (FIG. 1D), suggesting this likely to be aprimary effect of CM. Therefore, we tested whether knocking-down CMcells could restore p53 acetylation in CM-expressing. We transduced32D-CM cells with lentiviral vectors (HIV-7) [40] expressing 2independent shRNA (A3, D4) specifically against the CBFb-MYH11 sequenceand analyzed Ac-p53 induced by IR (3 Gy) at 6 h. Knocking-down CMresulted in restoration of Ac-p53 to similar levels as the control cells(FIG. 1E). We further assessed changes in p53 target gene expressionupon knocking-down CM (FIG. 1F) in primary leukemic cells isolated frominduced Cbfb^(56M/+)/Mx1-Cre mice. We discovered that CM knock-downresults in significant induction of p53 target expression even withoutadditional stimulation (FIG. 1G). Taken together, these studies indicatethat CM fusion protein expression impairs activation and acetylation ofp53.

CBFβ-SMMHC Forms an Aberrant Protein Complex with p53 and HDAC8.

To determine how CM fusion protein impairs p53 activity, we testedwhether the CM fusion protein interacts with the p53 protein. Weperformed co-immunoprecipitation (co-IP) with anti-p53 antibody followedby western blot analysis with anti-CBFβ antibody in 32D-CM cellscompared to 32D-CBFβ cells. The results showed that anti-p53 is able topull down CM fusion protein, but not CBFβ (FIG. 2A). Co-IP usinganti-Flag or anti-CBFβ followed by western blot using anti-p53 revealedsimilar results (FIG. 2B, data not shown). To assess whether CMinteracts with p53 in primary hematopoietic cells expressing CM atendogenous levels, we performed similar co-IP and western blot analysisusing pre-leukemic or leukemic cells isolated from pIpC inducedCbfb^(56M/+)/Mx1-Cre or Cbfb^(56M/+) control mice. Consistent withresults from 32D cells, we found that p53 forms a protein complex withCM in pre-leukemic as well as leukemic progenitor cells with or withoutIR (FIG. 2C). To assess the cellular localization of this complex, weisolated nuclear and cytoplasmic fractions for co-IP using anti-Flagfollowed by western blot with anti-p53 antibodies. The CM fusion proteinis present in both the nucleus and the cytoplasm, however, the complexwith p53 is detected exclusively in the nucleus (FIG. 2D). As analternative approach, we performed a Duolink in situ proximity ligationassay (PLA) to detect intermolecular interaction between CM fusionprotein and p53. We observed punctuate red fluorescent spots inCM-expressing cells but not the CBFβ-expressing cells (FIG. 2E), againindicating aberrant protein-protein interaction between CM and p53. Incontrast, similar Duolink in situ PLA using an Ac-p53 (K379) specificantibody showed very few interacting foci (FIG. 9), suggesting that CMinteracts with mostly deacetylated p53 proteins. To test whether thisaberrant interaction also occurs in primary human AML cells, weperformed co-IP with anti-p53 antibody followed by western blot analysiswith anti-CBFβ antibody in CD34⁺ cells isolated from patients withinv(16)⁺ AML compared to non-inv(16) AML. Interaction of CM with p53 isdetected specifically in primary inv(16)⁺ AML CD34⁺ cells (FIG. 2F).

It has been reported that CBFβ-SMMHC interacts with HDAC8 through theC-terminal SMMHC region [21]. Therefore, we assessed whether CM forms amultimeric complex with HDAC8 and p53 by sequential IP followed bywestern blot analysis to detect co-immunoprecipitating proteins. Weperformed primary IP with either anti-HDAC8 or anti-p53 antibodies, andsecondary IP with anti-CBFβ followed by western blot using anti-p53(FIG. 3A) or anti-HDAC8 (FIG. 3B), respectively. We detected amultimeric protein complex containing CM, p53, and HDAC8 inCM-expressing cells. To further examine whether the interaction of CMfusion protein and p53 is dependent on HDAC8 binding, we generated adeletion mutant of CM lacking 95 amino acids at the C-terminal region(ΔC95). CM-ΔC95 deletion does not bind HDAC8 (FIG. 10), however, it wascapable of binding to p53 as detected by co-IP and Duolink PLA (FIG. 3C,D). We also tested CM deletion mutants lacking regions containing thehigh affinity RUNX binding sites [18]. Both d134 (residues 134-236deleted) and d179 (residues 179-221 deleted) deletion mutants wereunable to bind p53 (FIG. 3C, D). The interaction of CM and p53 may beindependent of HDAC8 binding. We further confirmed this by knocking-downHdac8 in 32D-CM cells and performing co-IP and Duolink PLA assay. Weused lentivirus (pLKO.1) mediated expression of 2 independentsmall-hairpin (sh)-RNA sequences against Hdac8 to specificallyknock-down Hdac8 in 32D-CM cells (FIG. 3E, left). The binding of CM andp53 is unaffected in Hdac8 knocked-down cells (FIG. 3E right, F),confirming that the protein-protein interaction between CM and p53 isindependent of HDAC8.

HDAC8 Mediates the Deacetylation of p53 Associated with CBFβ-SMMHC.

Class 1 HDACs, including HDAC1, HDAC2, and HDAC3, reportedly couldinhibit p53 activity by deacetylating p53 [41-43]. Based on ourobservation that p53 acetylation is reduced and that CM forms a proteincomplex with HDAC8 and p53, without being bound by any particulartheory, we hypothesized that HDAC8 mediates the aberrant deacetylationof p53 in CM-expressing cells. To test this, we used lentivirus (pLKO.1)mediated expression of 2 independent small-hairpin (sh)-RNA sequencesagainst Hdac8 to specifically knock-down Hdac8 in 32D-CM cells. Cellswere exposed to IR (3 Gy) and analyzed for levels of p53 acetylation 6 hafter. Silencing of HDAC8 led to robust increase in Ac-p53 levels whiletotal p53 levels were not affected (FIG. 4A). To test whether thiseffect is dependent on the deacetylase activity of HDAC8, we used HDAC8isoform-selective inhibitors (HDAC8i) including PCI-34051 [44] orcompound 22d [45] directed against its catalytic activity. Treatmentwith both HDAC8i remarkably increased Ac-p53 in CM-expressing cells(FIG. 4B). Since p53 protein levels were also increased upon HDAC8itreatment, we included Mdm2 inhibitor Nutlin-3 to stabilize p53 protein.HDAC8i treatment (PCI-34051 or 22d) in combination with Nutlin-3enhanced Ac-p53 compared to Nutlin-3 alone (FIG. 4B), confirming thatthe effect of HDAC8i on Ac-p53 does not simply reflect p53stabilization. We also confirmed that HDAC8i (22d) treatment did notdisrupt the interaction of CM with p53, further supporting theinvolvement of deacetylase activity. In addition, expression of theCM-ΔC95 deletion mutant that was unable to bind HDAC8 (FIG. 9) had noeffect on Ac-p53 induction compared to control (FLAG or CBFβ) 32D cells(FIG. 4C). Similarly, expression of CM-d134 or d179 deletions incapableof binding p53 (FIG. 3C, D) did not alter induction of Ac-p53 levels inresponse to 3 Gy IR (FIG. 11). Collectively, these results indicate thatthe CM fusion protein recruits HDAC8 and p53 in a protein complex,thereby facilitating the deacetylation of p53 by HDAC8.

We next examined whether enhanced p53 acetylation translate intoincreased p53 transcriptional activity. Using qRT-PCR assay, we accessedinduction of p53 target genes in CM-ΔC95, CM, and CBFβ expressing cellsupon IR (3 Gy). For target genes assessed, we observed restoredactivation in CM-ΔC95 cells and a significant increase compared tofull-length CM could be detected for most targets (FIG. 4D). SinceHDAC8i treatment robustly increased Ac-p53 levels, we evaluatedactivation of p53 target genes upon treatment with HDAC8i PCI-34051 or22d. Variable levels of activation in p53 targets (Bax, Puma, p21,Gadd45b and LincRNA-p21) were observed (FIG. 4E), consistent with theenhanced p53 acetylation. Similarly, we observed activation of subsetsof p53 targets in pre-leukemic (FIG. 12A) or leukemic cells (FIG. 12B)expressing endogenous levels of CM. Together, these results support thatHDAC8-p53 protein complex associated with CM leads to aberrantdeacetylation of p53 mediated by HDAC8.

Pharmacologic Inhibition of HDAC8 Activates p53 and Selectively InducesApoptosis of Inv(16)⁺ AML Stem and Progenitor Cells.

Given that the frequency of TP53 mutation is relatively low in AML,altered post-translational modification by HDAC8 could represent analternative p53-inactivating mechanism and contribute to drug resistanceof AML stem cells. We first examined the expression of HDAC8 in CD34⁺stem and progenitor cells isolated from patients with inv(16)⁺ AMLcompared to normal mobilized peripheral blood stem cells (PBSC).Significant elevation in HDAC8 expression was observed in inv(16)⁺ AMLCD34⁺ cells (n=7; p=0.0003) compared to normal CD34⁺ cells (n=7) (FIG.5A). Therefore, we reasoned that inv(16)⁺ CD34⁺ cells might selectivelydepend on HDAC8 for proliferation and/or survival. To test this, wetreated inv(16)⁺ AML CD34⁺ cells and normal CD34⁺ cells with HDAC8i 22dfor 48 h. Dose responses to HDAC8i 22d (2.5 μM to 40 μM) were determinedby an ATP-based cell viability assay and Annexin V staining. Indeed,HDAC8i (22d) treatment significantly reduced proliferation of inv(16)⁺CD34⁺ cells compared to normal CD34⁺ cells (FIG. 5B, inv(16)⁺ AML n=9;normal n=7). Importantly, 22d HDAC8i selectively induced apoptosis ofinv(16)⁺ AML CD34⁺ cells compared to normal CD34⁺ cells (FIG. 5C) ornon-inv(16) AML (FIG. 13A). Modest cytotoxicity in normal CD34⁺ cellswas observed with higher dose (40 μM) of 22d, however, inv(16)⁺ AMLCD34⁺ cells were significantly more sensitive and were sensitive at alower dose (2.5 μM to 10 μM). Analysis of CD34⁺ cells from PBSC and CBshowed no significant difference (data not shown).

Similar to results obtained in mouse models, we detected protein-proteininteraction between CM and p53 in CD34⁺ cells isolated from inv(16)⁺ AMLpatients (FIG. 2F). We therefore tested whether inhibiting HDAC8deacetylase activity in inv(16)⁺ AML CD34⁺ cells could similarly lead toincreased p53 acetylation and transcriptional activity. We purifiedinv(16)⁺ AML CD34⁺ cells and accessed changes in p53 acetylation levelsupon HDAC8i (22d, 6h) treatment by western blot analysis. Indeed,elevated levels of Ac-p53 (K382) were consistently observed in allpatients examined (FIG. 5D, data not shown). Similar treatments with 22ddid not affect Ac-p53 in non-inv(16) AML (p53 non-mutated) CD34⁺ cells(FIG. 13B). Together with the selective induction of apoptosis, theseresults support a CM-specific mechanism underlying p53 inactivation.

Consistent with the enhanced acetylation, 22d treatment alsosignificantly induced expression of p53 target genes, particularlyapoptosis related genes (FIG. 5E; n=9). Similar treatment of normalCD34⁺ cells resulted in no or little change in p53 target expression(FIG. 5E, n=7). In order to determine whether HDAC8i-induced apoptosisis mediated by p53, we transduced inv(16)⁺ AML CD34⁺ cells with alentiviral vector (pLKO.1-GFP) carrying an p53 shRNA we confirmed couldeffectively knock down p53 expression (FIGS. 14A,14B). Transduced GFP⁺cells were sorted and exposed to 22d (2.5-40 μM). Despite theinter-sample variability, knocking down p53 expression led to reductionof 22d-induced apoptosis compared to non-silencing shRNA control in allAML samples tested (n=3) (FIGS. 5F and 5G), suggesting that p53contributes to the apoptosis effect induced by 22d HDAC8i in inv(16)⁺AML stem and progenitor cells.

Pharmacologic inhibition of HDAC8 abrogate leukemia initiating activityof CBFβ-SMMHC⁺ LSCs.

AML LSCs are functionally characterized by their capacity to engraft andreproduce AML disease in transplanted host. We reason that p53activation induced by HDAC8i could reduce or eliminate LSC engraftmentand leukemia-initiating capacity. To test this, we made use of ourmurine CM-induced AML model allowing for high-level engraftment andreproducible disease upon secondary transplantation. To facilitatetracking of CM-expressing AML cells, we created Cbfb^(56M/+)/Mx1-Cremice with a Cre-reporter line expressing tdTomato fluorescence proteinfollowing Cre-mediated recombination. AML can be induced inCbfb^(56M/+)/Mx1-Cre/tdTomato⁺ mice 3-6 months following pIpC and theAML cells are predominately dTomato⁺/cKit⁺ (data not shown). Freshlyisolated AML cells (2×10⁶) from BM of moribund animals were treated with22d (10 μM) or vehicle for 48 h before transplanting into sub-lethallyirradiated congenic recipients (FIG. 6A). Progression of AML disease isevident by increasing frequencies of dTomato⁺/cKit⁺ cells in theperipheral blood of mice transplanted with vehicle-treated cells whereasthese cells are barely detectable in mice receiving 22d-treated cells(FIG. 6B). At 8 weeks after transplantation, animals in thevehicle-treated group all showed enlarged spleens compared to the22d-treated group (FIGS. 6C, 15A). In fact, 2 out of 7 mice in thevehicle-treated group succumbed to lethal AML 5-6 weeks aftertransplantation prior to analysis of BM and spleen engraftment (data notshown). Analysis of BM and spleen at 8 weeks show significantly(p=0.025) reduced frequencies of dTomato⁺/cKit⁺ AML cells in micereceiving 22d-treated cells compared to vehicle-treated cells (FIG.6D-F). Likewise, the total numbers of dTomato⁺/cKit⁺ AML cells in the BMand spleen were also significantly (p=0.025) lower in 22d-treatedcompared to vehicle-treated group (FIGS. 15B, 15C). Finally, wemonitored AML onset and survival in a separate cohort transplanted withAML cells from Cbfb^(56M/+)/Mx1-Cre mice and treated with 22d (10 μM) orvehicle for 72 h prior to transplantation. We observed that 22dtreatment prevented AML reoccurrence in transplanted mice while morethan 50% of vehicle treated transplants succumb to lethal AML diseasewithin 4 months (FIG. 6G; p=0.0025). Transplantation of BM cellsisolated from diseased mice reproduced similar leukemia in all secondaryrecipients within 4 weeks (data not shown), confirming robust LSCactivity. To examine whether 22d treatment affects the engraftmentcapacity of surviving cells, we transplanted equal number (2×10⁶) of AMLcells treated with either 22d or vehicle in another cohort of mice(n=4). Similarly, 22d treatment reduced the engraftment of dTomato⁺ anddTomato⁺/cKit⁺ cells (FIGS. 15D, 15E) and enhanced survival (FIG. 15F),suggesting that the engraftment capacity is altered in addition toreducing AML cell survival.

We performed preclinical studies to determine the efficacy of in vivoadministration of 22d. AML cells (1×10⁶ or 2×10⁶) were directlytransplanted into sub-lethally irradiated congenic recipients. After 5-6weeks, transplanted mice were randomized into two groups, one grouptreated with vehicle and the other treated with 22d by intraperitonealinjection (50 mg/kg/dose) twice a day for 2 weeks (FIG. 7A). Flowcytometry analysis revealed significantly reduced the frequency(p=0.0097) and the number (p=0.0101) of dTomato⁺/cKit⁺ AML cells in thebone marrow of 22d treated mice compared to vehicle treated group (FIG.7B, C, D). To further assess the impact on LSC activity, we transplantedbone marrow cells (2×10⁶) from these treated mice into secondaryrecipients and analyzed for AML engraftment. Significant reduction inthe frequency (p<0.0001) and the number (p=0.0006) of dTomato⁺/cKit⁺ AMLcells was observed in the bone marrow 8 weeks after transplantation(FIG. 7E, F). Significant difference in spleen weight and AMLcellularity is also evident (FIG. 7G, data not shown). We monitoredleukemia onset and disease-free survival in another cohort of secondaryrecipients who received 5×10⁶ BM cells from 22d or vehicle treated mice.At 5-7 weeks after transplant, 60% (3 out of 5) of vehicle treatedtransplants are moribund with aggressive AML whereas all 22d treatedtransplants show no signs of leukemia (FIG. 7I, data not shown).Collectively, these results indicate that HDAC8 inhibition by 22dtreatment effectively reduces AML engraftment and eliminates theleukemia-initiating capacity of LSCs.

AML transformation requires multiple genetic and/or epigeneticalterations, which cooperatively impair differentiation, and conferproliferation and survival signals. Previous studies demonstrated thatCBFβ-SMMHC expression dominantly inhibits CBF/RUNX1 function anddisrupts hematopoietic differentiation [13,16,46,47]. It has been longthought that dominant inhibition of CBF/RUNX1 function underlies theleukemogenic function of CBFβ-SMMHC. However, recent genetic studiessuggested that CBFβ-SMMHC-mediated leukemogenesis requires functionalRunx proteins [22], and that RUNX1 dominant inhibition is not essentialfor transformation [23]. On the contrary, RUNX1 activity is now shown tobe required for the growth and survival of AML cells, includingRUNX1-ETO and CBFβ-SMMHC associated leukemia [24,25]. Recent genome widebinding analyses further revealed that CBFβ-SMMHC binds to target DNA ina RUNX1-dependent manner [48]. In this study, we show a novel mechanismof CBF-SMMHC-mediated transformation whereby CBFβ-SMMHC fusion proteindisrupts p53 activity through aberrant post-translational modification.It has been previously reported that CBFβ-SMMHC reduces p53 mRNAtranscription and slows apoptosis in Ba/F3 pro-B cell line [49]. We didnot observe significant changes in p53 mRNA or protein levels byCBFβ-SMMHC expression in 32D myeloid progenitor cell line (FIGS. 1B,16A) or in primary myeloid progenitor cells (FIGS. 1C, 16B). Sincetranscriptional activity of CBF is considerably context dependent, thispossibly reflects context specific transcriptional regulation of p53.Although p53 expression levels are not affected, we showed thatCBFβ-SMMHC notably reduced acetylated p53 levels (FIGS. 1 B and C) andforms an aberrant protein complex with p53 (FIG. 2 and FIG. 3). This isindependent of p19Arf/p16 ink4a given that this locus is inactivated in32D cells. We found that residues 179-221 of CBFβ-SMMHC are importantfor interaction with p53 (FIG. 3C, D), independent on the binding toHDAC8 at the C-terminus of SMMHC. RUNX1 has been shown to bind HDAC1,HDAC3, and HDAC9 whereas no binding to HDAC8 can be detected [16]. Giventhat normal CBFβ proteins do not interact with p53 (FIG. 2 and FIG. 3),the binding of p53 to CBFβ-SMMHC is unlikely to result from binding toRUNX1. Whether CBFβ-SMMHC residues 179-221 bind p53 directly orcontribute to unique conformational properties of CBFβ-SMMHC chimericprotein requires further investigation.

The acetylation of p53 promotes p53 stabilization, inhibits formation ofrepressive complexes and recruits cofactors for transcriptionalactivity. Histone deacetylases, including HDAC1, 2, 3 and Sirtuin I(SIRT1) are known to modulate p53 activity through deacetylating p53[41-43,50]. We found that CBFβ-SMMHC reduced acetylated p53 levelsparticularly at later time points after stimulation (FIG. 1B, C),suggesting that p53 is aberrantly deacetylated. We demonstrate thatHDAC8, similar to other class I HDACs, can deacetylate p53 and modulatep53 activity. Based on our results, we propose a model wherebyCBFβ-SMMHC impairs p53 function through protein-protein interactionresulting in recruitment of HDAC8 into a stable protein complex withp53, hence leading to aberrant deacetylation of p53 (FIG. 8).Remarkably, either knocking-down CBFβ-SMMHC or inhibition of HDAC8deacetylase activity substantially enhances p53 acetylation and p53target gene expression. The effect of HDAC8i on p53 targets is p53dependent because significantly reduced effect was seen when p53 isknocked-down (FIGS. 17A-17C). Our results also reveal that HDAC8i led toactivation of a distinct subset of p53 targets in pre-leukemicprogenitors (FIG. 12A) compared to leukemic cells (FIG. 12B), likelyreflecting the context-dependent and disease-stage specific activity ofp53.

AML is maintained by LSCs that are relatively resistant to chemotherapyand can persist as potential sources of relapse. Even though AML withCBF translocations are considered to have favorable prognosis, theincidence of relapse is still 25-58% with chemotherapy [51-53]. Novelstrategies directed to eradicate LSCs are required to improve treatmentoutcome. We show that inhibiting HDAC8 by an isotype-selectiveinhibitor, 22d, leads to restoration of p53 acetylation and activity,induction of apoptosis, and abrogates engraftment andleukemia-initiating activity of inv(16)⁺ AML LSCs. Whether additionalmechanisms besides increased apoptosis contribute to the reducedengraftment capacity remains to be examined. Importantly, this effect isselective for LSCs as normal HSCs display relatively low levels of p53target activation (FIG. 5E) and induction of apoptosis (FIG. 5C).Treatment of 22d also had no impact on short-term or long-termengraftment activity of normal HSCs (FIG. 18). This selectivity islikely due to the combined effect of elevated HDAC8 expression and therecruitment of HDAC8 and p53 into a stable protein complex in inv(16)⁺AML CD34⁺ cells. The increase in HDAC8 expression does not appear to bedirectly caused by CM expression since we did not observe changes ofHDAC8 levels in 32D cells expressing CM (FIG. 19). The impact ofCM-associated protein complex on HDAC8 activity requires furtherinvestigation.

Given that TP53 is rarely mutated in inv(16)⁺ AML, our results not onlyprovide insights into an alternative p53 inactivating mechanism but alsohighlight the potential therapeutic opportunity. Inhibition of MDM2 byNutlins and other inhibitors has been explored as an approach toactivate p53 in AML [54,55]. Various degrees of sensitivity andresistance influenced by multiple distinct mechanisms have beenobserved, underscoring the need to further dissect the heterogeneity anddistinct pathogenic pathways amongst AML subtypes. Many broad-spectrumHDAC inhibitors have potent anticancer activities, however, considerabletoxicity and lack of selectivity related to the pleiotropic biologicaleffects have greatly hampered their clinical application and efficacy.More selective inhibition of mechanistically defined HDAC targets isneeded to efficaciously eliminate cancer cells while minimizingtoxicity. It has been recently shown that selective inhibition of aclass III HDAC, SIRT1, enhances elimination of chronic myelogenousleukemia LSCs while preserving normal HSC function [56]. Herein, wediscovered that HDAC8 function can potentially be exploited to modulatep53 activity in AML and other cancers overexpressing HDAC8. Indeed,inhibition of HDAC8 results in reduced clonogenic growth and enhanceddifferentiation in neuroblastoma where high HDAC8 expression isassociated with poor prognosis [38]. Most broad-spectrum HDAC inhibitorscurrently used or being tested in clinical trails display low activityagainst HDAC8 [57]. Besides the selective hydroxamic acid inhibitorPCI-34051 previously reported [44], our team developed a series ofortho-aryl N-hydroxycinnamides as potent HDAC8 selective inhibitors withanti-HDAC8 activity superior to PCI-34051 [45]. Herein, we testedseveral HDAC8i in parallel and have found similar biological effectsconsistent with their HDAC8 inhibitory activities. In addition,inhibiting HDAC8 using 22d show a differential activity in enhancing p53acetylation in CBFβ-SMMHC expressing cells compared to other class IHDAC (MS-275), class III HDAC (TV6) or broad-spectrum (PCI-24781)inhibitors (FIG. 20). Together, these results suggest that the p53activating effects of 22d are not likely caused by off-target effectsand further support the selectivity of 22d towards HDAC8.

Without being bound by any particular theory, we propose a model thatCBFβ-SMMHC impairs p53 function through aberrant protein interactionwith p53 and HDAC8, and that HDAC8-mediated deacetylation of p53contributes to CBF 3-SMMHC-associated AML LSC maintenance (FIG. 8). Ourstudies reveal a novel p53-inactivating mechanism by the CBFβ-SMMHCleukemogenic fusion protein. The mechanisms underlying p53 inactivationis likely dependent on the context of oncogenic lesions and should beseparately defined in order to select optimal targets for intervention.Herein we have demonstrated methods for designing HDAC8-targetedtherapies to enhance eradication of inv(16)⁺ AML LSCs and which areexpected to be useful for other cancers. Our in vivo treatment studiesusing 22d show remarkable effectiveness in abrogating AML burden and LSCcapacity.

Example 5. Primers

Primers used in the experimental procedures disclosed herein are setforth in Table 10 following.

TABLE 10 Listing of primers SEQ Primer ID Gene Cells type Sequence NO:p21 Mouse Forward GCGGCTGTTTTTCTTGGTAG  1 Mouse ReverseAGACGAGGAAAGCAGTTCCA  2 Mdm2 Mouse Forward TTAGTGGCTGTAAGTCAGCAAGA  3Mouse Reverse CCTTCAGATCACTCCCACCT  4 Bax Mouse ForwardGTGAGCGGCTGCTTGTCT  5 Mouse Reverse GGTCCCGAAGTAGGAGAGGA  6 Bid MouseForward GACAGCTAGCCGCACAGTT  7 Mouse Reverse GGCCAGGCAGTTCCTTTT  8 PumaMouse Forward TTCTCCGGAGTGTTCATGC  9 Mouse Reverse TACAGCGGAGGGCATCAG 10Hprt Mouse Forward TCCTCCTCAGACCGCTTTT 11 Mouse ReverseCCTGGTTCATCATCGCTAATC 12 HDAC8 Human Forward GGTGACGTGTCTGATGTTGG 13Human Reverse GACACTTGCCAATTCCCACT 14 p21 Human ForwardTACCCTTGTGCCTCGCTCAG 15 Human Reverse CGGCGTTTGGAGTGGTAGA 16 HDM2 HumanForward CCTTCGTGAGAATTGGCTTC 17 Human Reverse CAACACATGACTCTCTGGAATCA 1814- Human Forward CTCTCCTGCGAAGAGCGAAAC 19 3-3σ Human ReverseCCTCGTTGCTTTTCTGCTCAA 20 PUMA Human Forward GACCTCAACGCACAGTACGAG 21Human Reverse AGGAGTCCCATGATGAGATTGT 22 ACTB Human ForwardGTGGATCAGCAAGCAGGAG 23 Human Reverse TTTGTCAAGAAAGGGTGTAACG 24

Example 6. Inhibition of HDAC8 and HeLa Nuclear HDACs

Results of inhibition studies of HDAC8 and HeLA nuclear HDACs bycompounds disclosed herein are tabulated in Table 11 following.

TABLE 11 Inhibition of HDAC8 (A) and HeLa nuclear HDACs (IC₅₀, nM) bycompounds 5a-h

A (relative Com- potency to HeLa pound R PCI34051)^([a]) HDAC 5a

0.29 >10000 5b

1.43 >10000 5c

1.17 >10000 5d

1.90 >10000 5e

1.86   8550 ± 0.12 5f

0.64 >10000 5g

0.28 798.4 ± 0.3 5h

0.63 836.0 ± 9.1 PCI34051 1 >10000 ^([a])Calculated from dividing theIC₅₀ value of each compound by that of PCI34051.

Example 7. Inhibition of HDAC8 and HeLa Nuclear HDACs and Cytotoxicityfor Compounds 6a-6f

Results of inhibitions studies of Cmpds 6a-6f and PCI-34051 aretabulated in Table 12 following.

TABLE 12 Inhibition of HDAC8 (A) and HeLa nuclear HDACs (IC₅₀, nM) andcytotoxicity (IC₅₀, μM) by compounds 6a-f

A (relative potency to HeLa Compound R PCI34051)^([a]) HDAC 6a H0.40 >10000 6b 2-OMe 0.17 >10000 6c 3-OMe 0.44 >10000 6d 4-OMe0.30 >10000 6e 3,4-diOMe 0.44 >10000 6f 3,4,5-triOMe 0.24 >10000PCI34051 1 >10000 ^([a])Calculated from dividing the IC₅₀ value of eachcompound by that of PCI34051.

Example 8. Inhibition of HDAC8 and HeLa Nuclear HDACs by Cmpds 15a-15e,21 and 25.

Results of inhibition studies on HDAC8 and HeLa nuclear HDAC8 by Cmpds15a-15e, 21 and 25 are tabulated in Table 13 following.

TABLE 13 Inhibition of HDAC 8 (A) and HeLa nuclear HDACs (IC₅₀, nM) bycompounds 15a-e, 21 and 25.

A (relative potency HeLa Compound R to PCI34051)^([a]) HDAC 15a 4-F0.38 >10000 15b 4-CF₃ 0.55 >10000 15c 5-OMe 0.06 >10000 15d 3,4-0.44 >10000 OMe 15e 3,4,5- 0.02 >10000 OMe 21 0.68 >10000 25 0.49 >10000PCI-34051 1 ^([a])Calculated from dividing the IC₅₀ value of eachcompound by that of PCI34051.

Example 9. HDAC8 Inhibition Activates p53 and Induces p53-DependentApoptosis in Human AML Cells

Survival of human AML cell lines upon contact with an HDAC8i (e.g. Cmpd22d) was investigated. As shown in the FIG. 21A, survival of each cellline (MV4-11, MOLM13, OCI-AML3 and KG1a) decreases with increased HDAC8iconcentration.

FIG. 21B demonstrates that increased HDAC8i concentration results ingreater signal for Ac-p53 and p53 by western blot analysis to assay theeffects of administration of HDAC8i (e.g. 22d) for 6-hr for Ac-p53, p53,Ac-H3, Ac-H4 and β-actin.

The fold change in mRNA levels of p53 targets after treatment withPCI-48012 for 16-hrs is depicted in FIG. 21C.

Western blot analysis of p53, b-actin and MV4-11 cells transduced withcontrol or sh-p53 is provided in FIG. 21D.

Example 10. Activity of HDAC8i Compounds on AML Cell Proliferation andSurvival

Relative survival of non-p53 mutated AML cell lines (MV4-11, MOLM13, andOCI-AML3) treated with HDAC8i compounds (Cmp[ds 22d, 5b, 5e, 5h) for48-hr was determined by Annexin V labeling and normalization tovehicle-treated controls. See FIGS. 22A-22C.

Relative proliferation of AML cell lines (MV4-11 and MOLM13) treatedwith HDAC8i (Cmpds 22d, 5b, 5e, 5h) for 48-hr was determined byluminescent cell viability assay, normalized to vehicle treated control.See FIGS. 22D-22E.

Resulting inhibitory activity of HDAC8i compounds is tabulated in Table14 following.

TABLE 14 Inhibitory activity of HDAC8i compounds on AML cell growth andsurvival. IC₅₀ (uM) OCI- MV4-11 MOLM13 AML3 MV4-11 MOLM13 Com- Apopto-Apopto- Apopto- Prolifera- Prolifera- pound sis sis sis tion tion 22d2.713 3.615 8.115 2.484 2.421 5b 0.5243 0.3453 2.352 0.0825 0.05327 5e11.92 11.7 12.48 7.494 3.358 5h ~22733 90.87 ~170501 16.59 7.174

Example 11. Apoptosis Studies, Cmpd 22D

Analysis of CD34⁺ cells from PBSC and CB showed no significantdifference based on cell origin upon contact with Cmpd 22d. See FIG. 23.

Example 12. Changes in p53 mRNA or Protein Levels by CBFb-SMMHCExpression

It has been previously reported that CBFβ-SMMHC reduces p53 mRNAtranscription and slows apoptosis in Ba/F3 pro-B cell line. We did notobserve significant changes in p53 mRNA or protein levels by CBFβ-SMMHCexpression in 32D myeloid progenitor cell line (FIG. 24A) or in primarymyeloid progenitor cells (FIG. 24B). Since transcriptional activity ofCBF is considerably context dependent, this possibly reflects contextspecific transcriptional regulation of p53.

Example 13. Gel Analyses of p53 and Ac-p53

The effect of agents PCI-24781, PCI-48012 and Nutlin on protein expressemploying Ac-p53, p53 and β-actin is depicts in FIG. 25.

Example 14. Effects of HDAC8 Inhibitors on Interaction Between p53 andCM

The effects of Cmpd 22d on IgG and IP expression were investigated. SeeFIG. 26A. Expression of after contact with Cmpd 22d on Ac-p53, p53 andβ-actin under various timing and wash conditions are depicted in FIG.26B. The survival rate with and without wash of Cmpd 22d is depicted inFIG. 26C, showing that washing of Cmpd 22d results in increasedsurvival.

Example 15. Inhibition of HDAC8 Selectively Activate p53 in Inv(16)+ AMLCD34+ Cells

Western blotting of Ac-p53, (K382), and p53 levels was conducted ininv(16)+ AML CD34+ cells upon contact with Cmpd 22d. Results aredepicted in FIG. 27A. The fold activation of the indicated p53 targetgenes in inv(16)+ AML CD34+ and normal CD34+ cells is depicted in thehistogram of FIG. 27B.

VI. REFERENCES

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VII. EMBODIMENTS

Embodiment P1 A compound having formula:

R¹ is substituted or unsubstituted C₁-C₂₀ alkyl, substituted orunsubstituted 2 to 20 membered heteroalkyl, substituted or unsubstituted3 to 7 membered cycloalkyl, substituted or unsubstituted 3 to 7 memberedheterocycloalkyl, substituted or unsubstituted 3 to 7 membered aryl, orsubstituted or unsubstituted 3 to 7 membered heteroaryl; and R² issubstituted or unsubstituted C₁-C₂₀ alkyl, substituted or unsubstituted2 to 20 membered heteroalkyl, substituted or unsubstituted 3 to 7membered cycloalkyl, substituted or unsubstituted 3 to 7 memberedheterocycloalkyl, substituted or unsubstituted 3 to 7 membered aryl, orsubstituted or unsubstituted 3 to 7 membered heteroaryl.

Embodiment P2 The compound of embodiment P1 having the formula:

Embodiment P3 The compound of any one of embodiments P1 to P2, whereinsaid compound is a HDAC8 inhibitor.

Embodiment P4 A method of treating cancer, the method comprisingadministering to a subject in need thereof a therapeutically effectiveamount the compound of any one of embodiments P1 to P3.

Embodiment P5 The method of embodiment P4, wherein said cancer is ahematological cancer.

Embodiment P6 The method of any one of embodiments P4 to P5, whereinsaid cancer is acute myeloid leukemia.

Embodiment 1 A compound having the formula:

A is cycloalkyl, heterocycloalkyl, aryl, or heteroaryl. X is —C(R⁴) or—N═. Y is a bond, —N(R⁵)—, —O—, or —S—. L¹ is a bond, —C(O)—, —C(O)O—,—O—, —S—, —N(R⁶)—, —C(O)N(R⁶)—, —S(O)₆—, —S(O)N(R⁶)—, substituted orunsubstituted alkylene, substituted or unsubstituted heteroalkylene,substituted or unsubstituted cycloalkylene, substituted or unsubstitutedheterocycloalkylene, substituted or unsubstituted arylene, orsubstituted or unsubstituted heteroarylene. R¹ is halogen, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —OR^(1A), —C(O)R^(1A), —NR^(1A)R^(1B),—C(O)OR^(1A), —C(O)NR^(1A)R^(1B), —NO₂, —SR^(1A), —S(O)_(n1)R^(1A),—S(O)_(n1)OR^(1A), —S(O)_(n1)NR^(1A)R^(1B), —NHNR^(1A)R^(1B),—ONR^(1A)R^(1B), —NHC(O)NHNR^(1A)R^(1B), substituted or unsubstitutedalkyl, substituted or unsubstituted heteroalkyl, substituted orunsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl,substituted or unsubstituted aryl, or substituted or unsubstitutedheteroaryl. R² is halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(2A),—C(O)R^(2A), —NR^(2A)R^(2B), —C(O)OR^(2A), —C(O)NR^(2A)R^(2B), —NO₂,—SR^(2A), —S(O)_(n2)R^(2A), —S(O)_(n2)OR^(2A), —S(O)_(n2)NR^(2A)R^(2B),—NHNR^(2A)R^(2B), —ONR^(2A)R^(2B), —NHC(O)NHNR^(2A)R^(2B), substitutedor unsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R³ is independently hydrogen, halogen, —N₃, —CF₃,—CCl₃, —CBr₃, —CI₃, —CN, —C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂,—NO₂, —SH, —S(O)₂H, —NHNH₂, —ONH₂, —NHC(O)NHNH₂, substituted orunsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R⁴ is hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(4A), —C(O)R^(4A), —NR^(4A)R^(4B), —C(O)OR^(4A),—C(O)NR^(4A)R^(4B), —NO₂, —SR^(4A), —S(O)_(n4)R^(4A), —S(O)_(n4)OR^(4A),—S(O)_(n4)NR^(4A)R^(4B), —NHNR^(4A)R^(4B), —ONR^(4A)R^(4B),—NHC(O)NHNR^(4A)R^(4B), substituted or unsubstituted C₁-C₅ alkyl, orsubstituted or unsubstituted 2 to 5 membered heteroalkyl. R⁵ ishydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN, —OR^(5A),—C(O)R^(5A), —NR^(5A)R^(5B), —C(O)OR^(5A), —C(O)NR^(5A)R^(5B), —NO₂,—SR^(5A), —S(O)_(n5)R^(5A), —S(O)_(n5)OR^(5A), —S(O)_(n5)NR^(5A)R^(5B),—NHNR^(5A)R^(5B), —ONR^(5A)R^(5B), —NHC(O)NHNR^(5A)R^(5B), substitutedor unsubstituted C₁-C₅ alkyl, or substituted or unsubstituted 2 to 5membered heteroalkyl. R⁶ is hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃,—CI₃, —CN, —OR^(6A), —C(O)R^(6A), —NR^(6A)R^(6B), —C(O)OR^(6A),—C(O)NR^(6A)R^(6B), —NO₂, —SR^(6A), —S(O)_(n6)R^(6A), —S(O)_(n6)OR^(6A),—S(O)NR^(6A)R^(6B), —NHNR^(6A)R^(6B), —ONR^(6A)R^(6B),—NHC(O)NHNR^(6A)R^(6B), substituted or unsubstituted alkyl, substitutedor unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl. R^(1A),R^(1B), R^(2A), R^(2B), R^(4A), R^(4B), R^(5A), R^(5B), R^(6A), andR^(6B) are independently hydrogen, oxo, halogen, —CF₃, —CN, —OH, —NH₂,—COOH, —CONH₂, —NO₂, —SH, —S(O)₂Cl, —S(O)₃H, —S(O)₄H, —S(O)₂NH₂, —NHNH₂,—ONH₂, —NHC(O)NHNH₂, —NHC(O)NH₂, —NHS(O)₂H, —NHC(O)H, —NHC(O)—OH, —NHOH,—OCF₃, —OCHF₂, substituted or unsubstituted alkyl, substituted orunsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl,substituted or unsubstituted heterocycloalkyl, substituted orunsubstituted aryl, or substituted or unsubstituted heteroaryl. n1, n2,n4, n5, and n6 are independently 1, 2, or 3. m1 is 0, 1, 2, 3, or 4. m2is 0, 1, 2, 3, 4, 5, or 6. m3 is 0, 1, or 2.

Embodiment 2 The compound of embodiment 1, wherein X is —C(R⁴)—.

Embodiment 3 The compound of any one of embodiments 1 to 2, wherein R²is halogen, —CF₃, —OR^(2A), —NO₂, substituted or unsubstituted C₁-C₅alkyl, or substituted or unsubstituted 2 to 5 membered heteroalkyl.

Embodiment 4 The compound of one of embodiments 1 to 3, wherein R² isOR^(2A), wherein R^(2A) is substituted or unsubstituted C₁-C₃ alkyl.

Embodiment 5 The compound of one of embodiments 1 to 4, wherein R³ ishydrogen, halogen, or —OR^(3A).

Embodiment 6 The compound of embodiment 5, wherein R³ is hydrogen.

Embodiment 7 The compound of one of embodiments 1 to 6, wherein m2 is 0.

Embodiment 8 The compound of one of embodiments 1 to 7, wherein Y is abond or —N(R⁵)—.

Embodiment 9 The compound of embodiment 8, wherein Y is a bond or —NH—.

Embodiment 10 The compound of one of embodiments 1 to 9, wherein L¹ is abond, —C(O)—, —O—, —NH—, substituted or unsubstituted alkylene,substituted or unsubstituted heteroalkylene, substituted orunsubstituted cycloalkylene, substituted or unsubstitutedheterocycloalkylene, substituted or unsubstituted arylene, orsubstituted or unsubstituted heteroarylene.

Embodiment 11 The compound of one of embodiments 1 to 10, wherein R¹ ishalogen, —CF₃, —NO₂, —NH₂, —OR^(1A), substituted or unsubstituted alkyl,substituted or unsubstituted heteroalkyl, substituted or unsubstitutedcycloalkyl, substituted or unsubstituted heterocycloalkyl, substitutedor unsubstituted aryl, or substituted or unsubstituted heteroaryl.

Embodiment 12 The compound of one of embodiments 1 to 11, wherein R¹ ishalogen, —CF₃, —NO₂, —NH₂, —OR^(1A).

Embodiment 13 The compound of one of embodiments 1 to 12, wherein R¹ is—OR^(1A), wherein R^(1A) is substituted or unsubstituted C₁-C₅ alkyl,substituted or unsubstituted 2 to 5 membered heteroalkyl, substituted orunsubstituted 3 to 6 membered cycloalkyl, substituted or unsubstituted 3to 6 membered heterocycloalkyl, substituted or unsubstituted 5 or 6membered aryl, or substituted or unsubstituted 5 or 6 memberedheteroaryl.

Embodiment 14 The compound of one of embodiments 1 to 13, wherein R¹ isR¹⁰-substituted or unsubstituted alkyl, R¹⁰-substituted or unsubstitutedheteroalkyl, R¹⁰-substituted or unsubstituted cycloalkyl,R¹⁰-substituted or unsubstituted heterocycloalkyl, R¹⁰-substituted orunsubstituted aryl, or R¹⁰-substituted or unsubstituted heteroaryl,wherein R¹⁰ is hydrogen, halogen, —N₃, —CF₃, —CCl₃, —CBr₃, —CI₃, —CN,—C(O)H, —OCH₃, —OCH₂CH₃, —NH₂, —COOH, —CONH₂, —NO₂, —SH, —S(O)₂H,—NHNH₂, —ONH₂, —NHC(O)NHNH₂, substituted or unsubstituted heteroalkyl,substituted or unsubstituted cycloalkyl, substituted or unsubstitutedheterocycloalkyl, substituted or unsubstituted aryl, or substituted orunsubstituted heteroaryl.

Embodiment 15 The compound of one of embodiments 1 to 14, wherein m1 is1, 2, or 3.

Embodiment 16 The compound of one of embodiments 1 to 15, wherein A isaryl or heteroaryl.

Embodiment 17 The compound of one of embodiments 1 to 16, wherein saidcompound has the formula:

Embodiment 18 The compound of embodiment 17, wherein

-   -   R² is halogen or —OR^(2A), wherein R^(2A) is hydrogen or        unsubstituted C₁-C₅ alkyl;    -   X is —CH₂— or —N—;    -   Y is —NH— or —O—;    -   L¹ is a bond;    -   R¹ is halogen, —NO₂, —NH₂, —OR^(1A), wherein R^(1A) is hydrogen        or unsubstituted C₁-C₅ alkyl; and    -   m1 is 1, 2, or 3.

Embodiment 19 The compound of one of embodiments 1 to 16, wherein A isaryl, 5,6-fused ring heteroaryl, 6,5-fused ring heteroaryl, or 6,6-fusedring heteroaryl.

Embodiment 20 The compound of embodiment 19, wherein said compound hasthe formula:

wherein A is 5,6-fused ring heteroaryl, 6,5-fused ring heteroaryl, or6,6-fused ring heteroaryl.

Embodiment 21 The compound of embodiment 20, wherein

-   -   R² is halogen or —OR^(2A), wherein R^(2A) is hydrogen or        unsubstituted C₁-C₅ alkyl;    -   X is —CH₂— or —N—;    -   Y is —NH— or —O—;    -   L¹ is a bond;    -   R¹ is halogen, —NO₂, —NH₂, —OR^(1A), wherein R^(1A) is hydrogen        or unsubstituted C₁-C₅ alkyl; and    -   m1 is 1, 2, or 3.

Embodiment 22 A method of treating cancer in a subject in need thereof,said method comprising administering an effective amount of an HDAC8inhibitor to said subject.

Embodiment 23 The method of embodiment 22, wherein said cancer is anon-mutated p53 cancer.

Embodiment 24 The method of any one of embodiments 22 to 23, whereinsaid non-mutated p53 cancer is acute myeloid leukemia (AML), acutelymphoblastic leukemia (ALL), lymphoma, neuroblastoma, glioma, bladdercancer, lung cancer, non-small cell lung cancer, breast cancer, ortriple-negative breast cancer.

Embodiment 25 The method of any one of embodiments 22 to 24, whereinsaid non-mutated p53 cancer is acute myeloid leukemia (AML).

Embodiment 26 The method of any one of embodiments 22 to 25, whereinsaid non-mutated p53 cancer has increased HDAC8 activity or HDAC8expression compared to a mutated p53 cancer.

Embodiment 27 The method of any one of embodiments 22 to 26, whereinsaid method further comprises prior to said treating, determiningwhether said cancer in said subject is a non-mutated p53 cancer.

Embodiment 28 The method of any one of embodiments 22 to 27, furthercomprising determining whether said non-mutated p53 cancer has increasedHDAC8 activity or HDAC8 expression.

Embodiment 29 The method of any one of embodiments 22 to 28, whereinsaid HDAC8 inhibitor is a HDAC8 inhibitor compound.

Embodiment 30 The method of any one of embodiments 22 to 29, whereinsaid HDAC8 inhibitor is a compound described herein.

Embodiment 31 The method of any one of embodiments 22 to 28, whereinsaid HDAC8 inhibitor is a HDAC8 inhibitor antibody, a HDAC8 inhibitorsiRNA, a HDAC8 inhibitor shRNA, or a HDAC8 inhibitor protein.

Embodiment 32 A method of inhibiting HDAC8 mediated deacetylation ofp53, said method comprising contacting HDAC8 with a HDAC8 inhibitor inthe presence of p53, thereby inhibiting HDAC8 deacetylation of p53.

Embodiment 33 The method of embodiment 31, wherein said contacting isperformed in vitro.

Embodiment 34 The method of embodiment 31, wherein said contacting isperformed in vivo.

Embodiment 35 The method of embodiment 31, wherein said contacting isperformed in an organism.

Embodiment 36 The method of any one of embodiments 32 to 35, whereinsaid HDAC8 inhibitor is a compound described herein.

Embodiment 37 A method of activating p53 in vivo, said method comprisingcontacting a cell with a HDAC8 inhibitor in the presence of HDAC8 andallowing said HDAC8 inhibitor to contact said HDAC8, thereby inhibitingsaid HDAC8 and activating p53.

Embodiment 38 The method of embodiment 36, wherein said contacting isperformed in an organism.

Embodiment 39 The method of any one of embodiments 37 to 38, whereinsaid HDAC8 inhibitor is a compound described herein.

What is claimed is:
 1. A compound having the formula (I):

wherein: R¹ is substituted or unsubstituted 2 to 20 memberedheteroalkyl, substituted or unsubstituted C₃-C₇ cycloalkyl, substitutedor unsubstituted 3 to 7 membered heterocycloalkyl, substituted orunsubstituted C₃-C₇ aryl, or substituted or unsubstituted 3 to 7membered heteroaryl; and R² is substituted or unsubstituted C₁-C₂₀alkyl, substituted or unsubstituted 2 to 20 membered heteroalkyl,substituted or unsubstituted C₃-C₇ cycloalkyl, substituted orunsubstituted 3 to 7 membered heterocycloalkyl, substituted orunsubstituted C₃-C₇ aryl, or substituted or unsubstituted 3 to 7membered heteroaryl.
 2. The compound of claim 1, wherein R¹ issubstituted or unsubstituted C₁-C₄ alkoxy and R² is a substituted orunsubstituted C₄-C₆ aryl.
 3. The compound of claim 2, wherein R¹ isunsubstituted C₁-C₂ alkoxy and R² is unsubstituted C6 aryl.
 4. Thecompound of claim 1, wherein the compound has formula (II):


5. A compound selected from the group consisting of:


6. A method of inhibiting HDAC8 mediated deacetylation of p53, themethod comprising contacting HDAC8 with the compound of claim 1 in thepresence of p53, thereby inhibiting HDAC8 deacetylation of p53.
 7. Amethod of activating p53 in vivo, the method comprising contacting acell with the compound of claim 1 in the presence of HDAC8; wherein thecell is an AML cell.
 8. The method of claim 7, wherein the AML cell isan AML stem cell.
 9. The compound of claim 1, wherein: R¹ is substitutedor unsubstituted 2 to 20 membered heteroalkyl, substituted orunsubstituted C₃-C₇ cycloalkyl, substituted or unsubstituted 3 to 7membered heterocycloalkyl, substituted or unsubstituted C₆-C₇ aryl, orsubstituted or unsubstituted 3 to 7 membered heteroaryl; and R² issubstituted or unsubstituted C₁-C₂₀ alkyl, substituted or unsubstituted2 to 20 membered heteroalkyl, substituted or unsubstituted C₃-C₇cycloalkyl, substituted or unsubstituted 3 to 7 memberedheterocycloalkyl, substituted or unsubstituted C₆-C₇ aryl, orsubstituted or unsubstituted 3 to 7 membered heteroaryl.